We're suckers for any project that involves Legos, and the DIY gurus at weblog Make play to our weaknesses with this saucy Lego recharger and key holder.
All you'll need is the appropriate Lego bricks (naturally), some screws, your devices' chargers, and a few common tools. The guide actually takes the process a little further than we would, cutting the ends of each device charger and fastening them to a Lego brick that, when connected to the base brick, completes the circuit and starts charging. (The process requires some wire stripping and soldering.) If we were to tackle this one, we'd probably skip all the messy cutting and soldering and just drape the plugs through the bricks rather than make dedicated Lego charger dongles out of them. Still, whichever route you take, the geeky end result is pretty nice.
If you want to get really serious about your Lego design, check out previously mentioned Lego Digital Designer to prototype and then buy the necessary parts.
Flashback: Lego Recharger [Make]