We do lot of interesting projects in asp.net & php, few days back we did a project with a company is USA, they
had installed a telecommunication server, that would allow conferencing. They need a interface that would bridge between server & users. We were to develop a UI interface in Web2.0, frontend powered in PHP & MySQL.
Depending upon the user invitees to be sent a conference owner would buy the package, the email would be sent to invitees with a unique code, where by all invitee would register with a password autogenerated for the confrence, the system would pass the user invitee details to conference server. Making access available automation to all invitee without any human interversion. Further, we enhanced the same system for the telecom based survey. For payments it was paypal.
Most interesting was passing the values from frontend to conference server and getting back the results. Owner of the system did not offered us any manual or sample code to accomplish that, but simple instructions on messengers. It was really awesome stuff we carried out, the best we loved it as well.