One Word: TiddlyWiki - personal, light-weight, off-line, extendable, free, cross-platform, tex-enabled wiki cum notebook. Its simply incredible. Everything in one html file. If you want to use latex jsmath is required. Just install Bob Mc. Elrath's jsmath plugin and you're in tex heaven.
Oh and did I mention there are hundreds of plugins which you can use to customize your tiddlywiki in endless ways. Here are a few of the prime plugin destinations where you can also download distributions of tiddlywiki with different sets of plugins for different users:
http://www.tiddlytools.com/
http://tiddlyvault.tiddlyspot.com/
http://tiddlywiki.org/wiki/Plugins
You can also find discussions of this amazing tool on other SE sites such as this one on superuser.SE.
There are some very neat plugins that allow you to easily create beautiful vector graphics for your notes. Both the MathSVG plugin by Paolo Soares or the Rafael javascript library are excellent.
Happy Wikiing !
This post imported from StackExchange Physics at 2014-04-01 16:20 (UCT), posted by SE-user user346