Err ... orkut was not actually strictly a google product because they didn't think up that idea as a product and worked on it. The guy who made orkut - Orkut Buyukkokten - was just working on his 20% free time to build it, and then they liked it and just released it as a product.

reference - http://searchenginewatch.com/3302741

Its kinda interesting that Google has developed only Gmail as an inhouse product till now !