The AP writer on Yahoo just reviewed digital pens. He likes the LiveScribe Pulse the best, the cheaper model of two pens the company produces. It sells for $149 from their web site. The more expensive $199 version has twice as much memory but he prefers "the cheaper model (which has) has room for 35 hours of audio at the highest quality setting, or more than 100 hours at a lower setting."
It is a sound recorder as well as a tool that remembers what you write which you can later transfer to your computer as a picture. The best feature is that you can insert "bookmarks" in your audio recording so you can find what you're looking for at a later date instead of having to listen to the whole recording. You can tap a place on your notes and the recording will go to what it heard when you wrote those words. You need to buy special paper with little dots on it that isn't prohibitively expensive. He says it's the best tool for taking notes during interviews or lectures besides an expensive tablet. Or even when writing about TV programs (my idea).