It is my opinion that you have learned the wrong lesson :)

What you should have done is separate personal stuff from public - not because you lend the device, but because people look over your shoulder.

E.g, I have two browsers, and use MicroB for usual stuff and Firefox for ... the rest, mainly because Fennec has the sync feature so it publishes the favorites.

Images I keep in RAW, either mine (as shot) or converted. They don't appear in the normal image thing you can show off. There's a RAW viewer implementation from some guy I owe a lot to :)

Videos you can keep in a format not listed or not understood by Nokia's player. I think the indexer looks at extensions, so there's that, however, MPlayer doesn't care. Alternately, use a codec that's different or simply use folders and exclude them from indexing. There's a tracker cfg app out there that eases you in.

I see no reason to make sacrifices just because you're a freak. If that were the case, N900 would come natively with a padlock, since we all need one. (not to mention it does, it's a lock code)

So, remember: It's a powerful device for a reason. So it can hold two lives at the same time. :D