Virtual Private Asterisk
Beave writes "These guys
have posted an interesting article on using
Virtual Private Servers to secure and even run multiple instances of Asterisk on one machine.
The article has in depth instructions on how to get such a beast up and running using hardware or emulated hardware (ztdummy driver). It's like running a small telco in a box!"
Don't forget to checkout www.cluecon.com /b
You can also come to Cluecon. Cluecon is a PBX Developers conference that will help to give you some ideas about what you can do with Asterisk and other VOIP technologies.
http://www.cluecon.com/
There are any number of SIP softphones, but I recommend using a softphone using asterisk's native IAX protocol. Check out the iaxcomm softphone for win32, linux and OSX: iaxclient.sourceforge.net/iaxcomm/index.html
Yes. Asterisk is a real, and very powerful open source PBX. With the requisite hardware you can hookup real phones, or use soft phones over SIP or IAX protocols, or use real TCP/IP phones (again SIP or IAX protocols), or hookup to a phoneline, or hookup to a VOIP number termination....
Everything you ever wanted to know: www.voip-info.org
Easy setup system: asteriskathome.sourceforge.net
General Info: www.asterisk.org
Hardware & Support: www.digium.com
NZ Electronics Enthusiasts: Check out my Trade Me Listings