More than 40 ex-Googlers have invested in about 200 companies including Twitter, Tesla Motors, Mint, Foursquare, Tapulous and more.The most active Google angel thus far is Aydin Senkut, a 40-year-old native of Turkey who has invested between $25,000 and $150,000 in more than 60 startups. Senkut joined Google in 1999 as its 63rd employee.