Today, Dave Caolo discovered what happens when your iPhone camera rolls past picture number 99999 (or so). As he and other Apple users have found, a picture count that goes too high can lead to unforseen errors. Human sacrifice. Dogs and cats living together. Mass hysteria. Or a camera roll that doesn't acknowledge new photos.

Snapped images are stored on your iPhone in your home folder. As user "mobile," that home folder is /var/mobile and the folder that stores your iTunes library, your voice memos, and your photos is /var/mobile/Media. Inside that media folder is a subfolder named DCIM.

Read on for more details.

If you're curious about developing for the iPhone, but haven't made the plunge yet, you might want to read Rogue Amoeba programmer Mike Ash's 22-step tale of developing NetAwake, which is available in the App Store.

It's a fascinating story, with a lot of waiting, a lot of rejection, and a lot of "screwing about in Xcode."

"The errors are essentially worthless. I believe I only ever saw Xcode generate one error, over and over and over again, as it encountered a whole bunch of different problems," he wrote.

The app took a month to approve, once it was submitted. Ash says that the people he corresponded with at Apple were "nice about responding to my query" but "spending a month in limbo for a single bug is a very poor tradeoff."

A short while back, Digg hosted a link to this crashed iPhone showing single user mode. In that case, the error message stated that the iPhone couldn't "exec /bin/sh for single user: No such file or directory." Now that the iPhone has been thoroughly hacked, this error has evolved somewhat.

Last night, TUAW friend DrunkDwarf crashed his iPhone but since he'd actually installed a copy of /bin/sh his error was somewhat different. Instead of complaining that it couldn't find /bin/sh, his iPhone simply... ran it. Not that this was much better news. Without a keyboard and no way to attach one, DrunkDwarf was a bit out of luck. He ended up having to do a restore.