Actually, Opera's bookmark syncing really does help me keep lists of websites in order. I can organize it into articles-to-read-later, grad-schools-to-look-up and whatnot, and it's kept in sync between my work and home computers. Any leaks won't really reveal anything Google's web history doesn't know already.

I'm also guilty of using my e-mail account as a TODO list and document store: I write myself a note of something which needs to be done, and delete it from your inbox once it's done.

For private notes, I usually just write it into a text file and leave it on my desktop or documents, and trust in Spotlight to find it again, but this is really extremely rare - I can't remember the last time I did this. If it's that important, I'll e-mail it to myself, so both Gmail and my home computer get copies of it which go into the appropriate folder, for registration numbers, orders, etc.

My getting-my-act-together five cents for today :-)