XCode 4.1 crashes on startup in Lion
Did you just install OSX Lion and XCode 4.1? Does it crash on you as soon as you try to launch it?
Your problem may be solved by simply re-installing iTunes. Yes, I know what you're thinking... "What the heck does one have to do with the other?" I have no idea. But this appears to resolve many people's problems. Just go to http://www.apple.com/iTunes and download it and install.
See this discussion for more details: https://discussions.apple.com/thread/3188708?start=15&tstart=0