Updated so John doesn't have to.
PNotes is a sticky note utility that allows you to post sticky notes on your screen. It has multiple display options as well as a handy feature to schedule notes to pop up. It's small (under 1MB) and works well on Windows 2000 and up.
PNotes Portable 2.5.0.101 Pre-Release 1
(may take a few minutes to hit the download servers)
Edit: Just realised 2 things. One, I accidentally left in Notes.pndb in App\PNotes. Delete as you will. Two, it doesn't change the location of the Notes.pndb. I'll wait for an update from Lamer, but until then, don't count this as an official pre-release.
Edit 2: Now uses 101 as mentioned below, so should be fully working now.