Developers using the OpenSocial API can now reach tens of millions of iGoogle users! As of this week, iGoogle now supports OpenSocial in both the US and Australia, with the plan to roll it out to more users soon. In general, we think "social is better" when it comes to the web - activities such as reading the news, doing a crossword puzzle, sharing a todo list, or watching a video are all better when done with a friend. These are all things that iGoogle users love to do, so making them social on iGoogle was the next logical next step.
If you're interested in getting started writing social gadgets for iGoogle, check out the full announcement on the iGoogle developer blog.