I only discovered geektools yesterday and some of the things people have achieved are stunning. I've had this picture of my FTO as wallpaper for a long time off and on. I took the picture about five years ago but only edited out the number plate tonight before posting. I've now made the space invader a permanent feature.
I took a lot of ideas from pconigs here http://iamawesome.net/2009/04/my-geektool-setup/ but just enhanced my existing desktop.
I did write the geeklets to pull the wind detail and sunrise and sunset data from Yahoo weather myself, adapted the one pconigs describes above including how to adapt it for your city.