Evernote is an service/application you can use to store notes, images and all kind of information (like audio, handwritten or video notes) for retrieving later. It supports search and tagging and most importantly: you can sync everything between computers - further more, Evernote supports mobile devices too like iPhone, Windows Mobile, BlackBerry or Android and there's a web interface too and a clipping bookmarklet to pull anything into your netbook. But unfortunately there's no official Evernote application for Linux.
Nevernote is an open source clone of Evernote that works on Linux. While Evernote now runs on Linux through Wine, the application is quite slow so you may want to try Nevernote.