BasKet Note Pads is a neat little KDE application for note-taking and idea organisation. It's actually pretty neat and it has some cool features.
The core idea behind BasKet is that you can keep several different 'baskets', in which you store snippets of information - text, images, web links etc. Instead of noting down all your ideas, todos and other little bits of information, you keep them in a basket and you can easily find them later.
I'm finding it quite useful, actually, and it works even if you don't run KDE as your desktop environment (although it's better if you do).
To get BasKet, search for 'basket' in your software management program, or you can download source code (and a couple of pre-packaged versions) from the official website.