We’re delighted to announce that Y Combinator is getting two new partners, the first we’ve added since we started YC in 2005.

In case anyone doesn’t already know who he is, Paul Buchheit was responsible for three of the best things Google has done: he wrote GMail, built the original prototype of AdSense, and came up with the phrase “Don’t be evil.” After leaving Google he started FriendFeed, which last year became Facebook’s largest acquisition to date. He’s a good friend as well as one of the world’s best hackers; for years we’ve considered him an honorary YC partner.

We hired Harj Taggar earlier this year to work advising startups alongside me. He wasn’t technically a partner, but we quickly realized that he was one de facto—that among us his opinion carried as much weight as any of ours—and that it would be mean of us to delay recognizing this officially. Harj’s arrival significantly improved how well YC operated. He’s a large part of the reason we were able to fund 36 startups in the summer 2010 cycle.