It is really fun. If you have free time, just try to code small gadget using Google Desktop API. It is really not much difficult thing ;-). This SDK lets us create gadgets and indexing plug-ins for Google Desktop.
for more info
After creating your gadget, you can submit the software. Then Google will do a review and if your software performs well, they will approve it. Then you can find it by selecting the appropriate category from the links on the left side and scrolling down to your listing.
To reward your creative talents, they would give you a limited edition Google Desktop Developer's patch or ........bla bla bla .. :D
I have developed small gadget so far and I am happy to say that they approved it. :)
So its time to develop more and more gadgets......... hope you will too.. cheers