I recently ran across the temperature logger tutorial posted a while ago by jennajane, and wanted to chime in. First of all way to go! I started my path to learning Arduinos with the same Adafruit logger shield not very long ago, and it's been an entertaining hobby for me ever since. But I have been plugging away at it for a while now, and I just posted a DIY plan for a very inexpensive ($10-15) logger based on the sparkfun Pro Mini boards. Also there is a waterproof housing I made from PVC pipe with only one hack-saw cut & some PVC adhesive for about $10.