It's really easy to delete stuff on the N900--just click that garbage icon and confirm and away it goes.

Well. What if you decide five minutes later you really did want that file?

There's a great utility called PhotoRec that can scan your FAT partition (MyDocs or N900 if you connect to a PC in Mass Storage mode) and recover files based on their type. There are much more basic undelete utilities around, but why not use a sledgehammer?

You'll need a microSD card to use the utility. It saves the stuff it finds while scanning and you can't put it on the drive you are scanning, and don't want to fill root. You could try putting it in your home directory, but be careful not to fill it. That also is going to compete with the scanning because it's the same flash device.

This is procedure not without risks and i haven't made a nicely packaged app--it's a binary executable gzipped and attached. Save it to your media card, transfer it to your home directory, gunzip it, and run it.

I'll say again: this is not an idiot-proof process. I'm uploading this because it came in useful when i needed to recover a file, and it may be useful to others. Use at your own risk.

In an incredibly coincidental bit of timing, a package including this tool was announced at the same time i made this thread. You can get your recovery tool either way.