Evernote

Another 'must have' program is Evernote...

It is similar to OneNote but it synchronizes data to the web (free account or paid account options)- and there are, PC, Apple and PocketPC clients that can all access the same data. 

I find it useful to create a list of things to do on my PC and then I can view them on my HTC touch- or to take notes on my phone and have them appear on my PC at home.

One VERY useful thing I did was to put all of my DVDs in a list and post them into a notebook in EverNote- so now when I see a movie at BestBuy or Fry's and I cannot remember if I already own it (early senility is starting to set in) I can do a keyword search and know for sure...

The ability to embed hyperlinks and PDF files (and other formats) also makes it useful for working on projects (such as my CarPC project).