I was working on my iPhone game on Sunday, and wanted to load the latest build onto the device so I could test some stuff out. When the build came up on the screen, the main menu looked suspiciously like the old version of the game, and didn't contain the new test map I wanted to try out. I figured I did something wrong so I went back to XCode to 'Clean' and 'Build' my executable again...and received an Error in the output.
It ends up my iPhone developer certificate had just expired. In hindsight, I'm very glad this issue came up when it did. Since it was a Sunday I had the extra time to renew my iPhone dev certificate, and because the change I wanted to test was obviously not there, finding the underlying issues didn't take very long. It was an annoyance though. I ended up wasting about 20 minutes getting my stuff back in order and at the point I could build against my device again.
Oh well, at least I don't need to worry about this again until next year.