Google Gadget anyone?

I just heard about the possiblity of creating a gadget that one could embed on iGoogle that would list books out, due dates, etc.  I want this!  As an avid used of various gadgets to make my life easier and at least quasi-organized, I can see this being very iuseful.  Anyone out there know how to code gadgets?  I think it would be a great addition to the creation of the Horicon Virtual Library.