Source: snapvoip.blogspot.com

The VOIP Users Conference has arranged a live interactive conference on January 4th, 2008, at 12:00 PM Eastern USA (11:00 AM CDT, 9:00 AM Pacific). The special feature of this session is that Mark Spencer, creator of Asterisk, a Linux-based open-sourced PBX and the founder, chairman and CTO of Digium, joins the VoIP Users Conference live for discussion and questions about asterisk and Digium.
The VoIP Users Conference is a weekly live interactive podcast about Voice over IP produced by Talkathon.org. The object of the Friday conferences is to discuss all aspects of VOIP, including applications, services, products and development.
Anyone can join the conference on a regular phone by following instructions given at http://VoipUsersConference.org. It is also possible to connect Asterisk directly to the conference server via SIP or dial in directly from a SIP client. Details are on the site. Listen anonymously using the player at http://food4wine.ning.com which is the Conference Community site. Talkshoe was discussed here.

Listen to recorded shows as there is a conference on every Friday.
listen to the live stream or recordings.

To call in to live conferences, you should sign up (free) at http://www.Talkshoe.com

How to configure your Asterisk to talk with talkshoe.

; In extensions.conf: define your PIN and the show id

[globals]MY_PIN=0123456789 ; whatever 10-digit pin you register at Talkshoe.com

;;; You can now use 1# as a PIN;;; However, this makes it hard for me to see who's there to call on you;;; It would be great of people would create Talkshoe accounts and use names we can call on to speak.;;; Either their IRC pseudos, company names or name/initial like;;; Digium_guys, Steve_S, f_williams, Zeeek, russellb

CONFERENCE_CODE=22622 ; Voip users conference Talkshoe show ID

VOIP_USERS_CONFERENCE=1234 ; whatever extension you want to use to reach the conference

; Put the extension in a context, such as "talkshoe"; (and make sure the context is included in a context you are going to dial from)

[talkshoe]exten => ${VOIP_USERS_CONFERENCE},1,Dial(SIP/123@66.212.134.192,60,D(${CONFERENCE_CODE}#${MY_PIN}#))Important: Recent Talkshoe conference hardware changes may make the DTMF not work.Enter codes manually if you have problems. 

Source: snapvoip.blogspot.com

TMC, the ever resourceful telecom powerhouse, has partnered with Fonality to launch trixCon: The Open Communication Conference. It will be January 24-25, 2008 at the Miami Beach Convention Center.

trixCon will feature a dedicated presentation theater and exhibition on the INTERNET TELEPHONY Conference & EXPO East 2008 (ITEXPO) show floor. Attendees seeking open source telephony solutions can attend free educational sessions and visit leading vendors showcasing the latest open source products and services.

Registration for INTERNET TELEPHONY Conference & EXPO is now open at www.itexpo.com. Admission to trixCon is included with any ITEXPO registration plan. Vendors interested in participating in trixCon should contact Dave Rodriguez at 1-203-852-6800 x146.

Source: snapvoip.blogspot.com

I came across this package a while back and have been playing a bit with it. But I really got it working after Dan Austin released the version 3.0 just a two days ago. Then again I had to switch to SVN version in order get it completeley working.
Managed conferencing solution using Asterisk, Web-MeetMe and a database-driven scheduler. From the projects readme.
Web-MeetMe for Asterisk
Web-MeetMe is a collection of PHP pages that leverage
the database for scheduling and the Asterisk Manager interface
to monitor and control active conferences.

The scheduler currently supports these features:
+ Conference number conflict avoidance
+ Recurring conferences
* Daily, weekly or bi-weekly
+ Enforces a user password if a admin password
is set
+ Seperate views for past, current and future
conferences
+ Editing future conferences
* Includes a series of conferences
+ Deleting past conferences
+ CDR-like view of past conferences
* Includes a link to conference recordings
+ One click features to-
* Extend an active conference (time)
* Kick out all participants
* Out-call to include participants
+ Optional early join features
* fuzzystart allows a caller to enter a
room early (in seconds, set in cbmysql.conf)
* earlyalert notifies a call that their
conference has not yet started, if they
enter a valid conference number and the
conference is scheduled to start soon.
(in seconds, set in cbmysql.conf)

App_cbmysql
When combined with a database, MySQL or Postgress,
CBMySQL can authenticate a caller, verify that the conference
they are attempting to join is scheduled and enforce the
maximum participent count.

CBMySQL can distinguish between a conference
administrator and a standard user based on pins. Different
options may be set in the configuration file to join the
caller to the conference based on their status. A standard
user might be joined in a listen only mode as an example.

CBEnd
CBEnd is a small PHP script that monitors for active
conferences. When it identifies a current conference, it checks
the scheduler database and enforces the conference duration.
The default behaviour is to announce that the conference is to
end five minutes before the scheduled end time. This allows the
conference owner or administrator to update the conference using
Web-MeetMe to extend the duration.

CBEnd uses the Asterisk Manager interface to issue commands
to the conferencing application. The current commands include
identifying active conferences and the ‘Kick all’ command.

This script is also responsible for maintaining the
CDR tables. The script is optional, but not using it limits
the overall system functionality.

** Installation
* Dependencies
- Asterisk 1.4 or later
- MySQL 3.23 or later.
!! Other databases may work, but testing
!! and development have been against MySQL
- PHP 4.3 or later
!! Reports depend on mod_gd and GD-2.0.28
!! or later
!! PEAR::DB (php-pear)

* Install Web-MeetMe
Download the latest Web-MeetMe tgz file from
http://www.sf.net/projects/web-meetme and extract it to your webservers
document root.
* Setup the database
Create a table called booking in your database. The
table is described in ./cbmysql/db-tables-v5.txt

* Compile and install CBMySQL
App_cbmysql is now included in the web-meetme package,
located in ./cbmysql. To install just run make; make install

Copy the sample cbmysql.conf to /etc/asterisk and create
a dialplan similar to the one in cb-extensions.conf.sample
Modify the settings to suit your system. The location of the
mysql.sock file is likely not correct, check /etc/my.conf for
the correct location.

Modify the ../web-meetme/lib/defines.php to match you
database settings.

Copy ../web-meetme/phpagi/phpagi.example.conf to
/etc/asterisk and modify it to match the settings in your
manager.conf

If you intend to use the authentication functions,
it is strongly recommended that you use SSL and force all
conenctions to the Web-MeetMe pages to use HTTPS.

* LDAP or Active Directory integration
Edit ./lib/defines and set the AUTH_TYPE to adLDAP.
Set the ADMIN_GROUP to appropriate list, the default is
"Domain Admins", but you might not want the network folks
controlling your telephony systems. Optionally you can
chanege the browser session timeout.

Edit ./lib/adLDAP and replace all instances of
"yourdomain" and "yourserver" with the values for your
network.

* Usage
If all of the steps have been followed, you should be
able to open your browser, connect to the Web-MeetMe page and
schedule a conference. A new conference start time defaults
to the time it is scheduled, so modify it if needed. Any
required fields that are left blank will be auto-generated.
Note the conference room number and password.

Dial the number you have assigned for conferencing, and
try the conference you have just added. If the time and password
are correct, you will be joined to the conference.

You can now use the Web-Meetme monitor function to manage
your conference.

Links;
Web-Meetme download
Asterisk IPPBX