Hiya Hoola...
A little thing I just tried is this:
It's a "post-it" type app that comes with windows sidebar that can be "detached" and moved to wherever on the screen you want it. I usually refer to paper notes (flip-type index cards) though... for quicker access.
I agree that some form of built-in note-tool would be a welcome addition for most, as long as it didn't use too much of our system resources and was unobtrusive. I must admit, my memory isn't what it used to be. :/
Check out andyson's profile. He's made a "WGT Friends Info Template" for Excel (scroll down through his blog posts) that also comes in handy for those of us with CRS syndrome. :)