This post on the blog Digital Ethnography sent me to the Livescribe site to look at their smartpen. It records audio. In conjunction with coded paper in a notebook, you turn the recording on and off. It also transfers your notes to your computer as images and OCRs (?) them so you can search them. I figured they would make their money from the paper, but they say you can print your own. (Of course, you have to give up your favorite pen and notebook.)
I haven’t investigated this in detail — am posting this in the hope that a reader either has or will investigate further and let us all know, in more detail, what it does and whether it lives up to its promises.