Brent Thompson wrote to tell me of Greg Warnock's Junto Partners, a program for identifying and encouraging young entrepreneurs that seems similar to Paul Graham's Summer Founders Program. Brent participated in Junto Partners and says:
Being part of Junto has been invaluable--and not because of any funding potential. The things I would consider most valuable are the networking and mentoring. Additionally, simply being part of something sponsored by a well-known entrepreneur has been great for getting first meetings and a little unsolicited attention.