Which google products come from Google employees' 20% spare-time?

Question

I'm looking for specific product names, such as Gmail, Gmaps, etc.

Answer 1

There really is only one product that came from the "spare-time" idea. Which is Orkut the social networking product, named after its creator, Google employee Orkut Büyükkökten. Sadly the product has been a total flop in the US with only 4 million users.

Other popular products from google weren’t even built by google but purchased from other companies:

Google maps is actually Keyhole Technology.
Blogger and Picasa were also an acquisition.