[Asterisk-Users] Telephony Portal w/ Asterisk

[destan]

I was planning on setting up a web site/service like Net2Phone or maybe FWD,
to give VoIP service. I think this can be setup using * pbx, by giving every
user an extension and so on. Maybe I have to code a web interface for 
registration
and profile editing, but other than that, softphones would automatically
register with * anyway right? Should I use * or try something like SER? 
Anybody
done anything like this with asterisk? 

ps: BTW, thanks for the answers for my log question.
Umut