I've registered for
Google Apps in order to make use of
Google Docs. This online application allows me to make ongoing notes on all topics wherever I may be and the basic version I have signed up for is free (you get 2GB online storage which is more than enough for me). The GUI is excellent for an online application and includes useful features such as auto-saving as you go along, straightforward image upload & insertion, and I can download and convert a document into another format in a couple of clicks. e.g. to MS Word, PDF etc. And, of course, being Google you can search through all of your documents too.