Evernote for Linux: Nevernote
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 supports most of the Evernot features so you can easily drag and drop images or PDF files, tag or preview notes. Unfortunately, there are some features which are not supported by Nevernote: you can't write ink notes or record webcam notes, there is no screen clipper (but you can use Shutter instead!), emailing only sends a plain text note and also the sharing feature is missing.