There are several Job Alchemy above being one of them. There's one in the UK (who's name I can't remember right now) which specializes in "referal" hiring, ta

There are several Job Alchemy above being one of them. There's one in the UK (who's name I can't remember right now) which specializes in "referal" hiring, taking advantage of the fact many large employers give employee's significant bonuses for referred hires to essentially create a secondary market for recruitment based upon referal bonus payments.