Lifehacker reader kadavy drew inspiration from Merlin Mann's Hipster PDA to create an on-the-go, pocket-friendly Hipster PDA Keychain. There's not much you need to know about this one beyond the idea—as you can see, the execution is dead simple. Just attach a binder clip to your keychain, cut up some notecards, and you're good to go. This picture was uploaded to Flickr years ago, but we had never seen or featured it. In fact, we just stumbled onto it by chance while doing a little Flickr searching yesterday. Still, we love it. Nice work, kadavy! While you're enjoying some DIY keychain hacking, check out previously mentioned favourites like the keychain money clip, Leatherman keychain, and the DIY compact keychain.