2011-08-06: UPDATE: now available from my drupal.org sandbox
About two years ago, I created a small module intended as a proof-of-concept for a Drupal base API to generate Google Gadgets, with a sample gadget providing direct access to the Drupal API search.
Of course, at the time, the module was for D5. Various people expressed interest for the concept, including a note by AgentRickard about a possible update to his existing Drupal gadget container, module MySite, of a similar feature.
However, nothing seemed to come out of the discussion, and the subject just drifted.
Now, with renewed interest from the new Drupal Media SIG on the french GDO, I've updated the module to D6 and made it easier to download: it is now just attached to this page.
If you want to try it in your iGoogle, the module is enabled on this site at http://blog.riff.org/gadgets/api
UPDATE 2018-04-14: you will need to port the module to D8. Since iGoogle was deprecated by Google and the Gadgets API around 2014, I never ported the module to D7 or D8.
If anyone finds it useful as a starting point, I can of course put it in my d.o. sandbox or create a project for it so we can further evolve it.