I don't normally talk about tools on my blog, but I found one that really works for me. It's called Evernote. It allows me to keep notes, clip web sites, my Twitter feed, or even pictures. Everything can be organized in folders and searched. As I'm adopting the techniques of Getting Things Done, I find Evernote helps with the organization.
What I really like is the sync capability. I can take notes on my work computer and access them through my home computer or my iPod touch. So if I'm at work and think of something to put on my personal to-do list, I can add it and know when I get to my home computer, it will be there. I can also access all my notes from a website if I'm not at any of my computers.
The desktop works on OS-X & Windows. There's iPhone/iPod Touch and Windows Mobile versions. The basic subscription is free, you just have to put up with a tiny ad in the corner. The paid subscription is only $5/month and includes higher encryption, more storage etc.