My experience running PHP on IIS 7.5
After searching on the net, I found this article. After following the instructions given I was able to make php work nicely. There were some hiccups like not being able to see error messages, etc. Most are just changes in settings and can be done in the local php.ini file.
The set up has been running for over 2 months now without any problems. No server crashes, app restarts or anything like that. Seems like a good platform option.
Microsoft also provides an integrated install for PHP through the web platform installer available here.