You can sign up with TrafficClub.Com that uses Google, DomainSponsor and Skenzo. You get to assign the percentage of traffic among them, from 0% to 100%.
My experience is that Google pays the least of the three. So I end up assigning traffic of 0% to Google, a small portion to Skenzo, and the bulk to DomainSponsor.
Then there is the newcomer iMonetize.Com which has even more choices than TrafficClub, but I've not yet signed up to try. The ones that are using iMonetize don't seem to have much detail to share in terms of their experience with the service.