Lately I've been trying to keep track of everything on index cards. I like the low-tech approach, and I've always been an office supplies geek at heart anyway. It turns out I'm not alone: 43folders has a whole category for index cards. They even go so far as to call a stack of cards held together with a clip a "Hipster PDA". Jazzmasterson (if that is his real name) has a detailed photo essay demonstrating his index card system. My system is far less elaborate, but works well nonetheless. Low-tech to the rescue!