[Anthony] has transformed a simple router board into a fully fledged Debian system. The board is an RB433AH which has a 680Mhz development board with 3 LAN ports and 3 Mini PCI slots intended for routing tasks. At roughly $150, this could be a pretty versatile tool to have around. Possibly more useful than the SheevaPlug.
We’ve covered automated plant growing before, but that project might be overkill for many situations. Many of us don’t need our plants to have facial expressions either. Sometimes, we just need a little bit of help. This automated grow light is a nice little project that supplies decent light when necessary. You can download the source files on the tutorial. It is currently set to supply an additional 4 hours of light, detecting the low light levels to turn it on.