Evernote is my new grab bag for data-like stuff. (as opposed to my Timbuk2 bag, which is my grab bag for real stuff.)
Primarily because:
1) It syncs! You can get, add or edit your data on the web, on the desktop and on the iPhone. And sync works.
2) You can encrypt snippets within a note. So, I have login info for client sites and I encrypt just the password. The other info is readily available without having to encrypt the entire note.
3) It's free! (they've started throwing ads at me, fine keep it up). Your use is capped at the free level, but I've not come even close to hitting the cap.
4) Throw all kinds of documents at it (free account is limited to pdfs, I think. Paid version will let you add more). I have a 2 meg pd of the SF Muni system. I've started throwing pdfs of receipts in.
5) On the iphone you can add voice notes. On the desktop, you can add 'iSight' notes (it's a Mac thing.).
6) It'll parse the text out of graphics. So, take a picture of receipt or business card or something and upload it and search for it later based on the text! (crazy.)
7) Email and or Twit directly to your 'notebook'. It's painfully easy to get data into the system.
Just too cool for school.