Evernote is a popular app for the iPhone and iPod Touch. (There are also PC and Mac versions.)
You can write notes and record photos from the iPhone camera. Notes are synced to Evernotes servers and to all your devices. You can organize and search your notes. Evernote even does OCR (optical character recognition) on images so you can search for text in images.
It's a great product and many people swear by it.
The software is buggy. It freezes. It crashes. You have to reinstall it periodically to get it working again. Check out the problem reports on GetSatisfaction for more examples.
A tool like this is only worthwhile if it's dependable. I put all my travel information in it and it died almost as soon as I left home. That doesn't make a happy customer. (thankfully reinstalling got me going again)
I'm not the only one with a love hate relationship with Evernote. People give up on it, come back thinking it's fixed, only to discover some time later (after entering a bunch more notes) that it's still got bugs, just a different set from before.
I'm not sure where the problem lies. But if they want to be successful in the long run they have to do better.
Quit adding new features until it's more stable. Add more automated tests. Set up alpha and beta testing progroms. Review the code. Refactor the code. Throw out problem code and rewrite it. Whatever it takes. I can't see anything more important.
It's a good product but it doesn't matter how many great features it has if it's not reliable.