Bare Bones Software : YOJIMBO
Yojimbo-Your effortless, reliable information organizer for Mac OS X. Yojimbo makes keeping all the small (or even large) bits of information that pour in every day organized and accessible. It’s so simple, there is no learning curve. Yojimbo’s mechanism for collecting, storing and finding information is so natural and effortless, it will change your life—without changing the way you work.

I have been using Yojimbo for six months and it has become indispensable. If you have a Mac – check it out!