Alternatives To Adsense
BidVertiser
Bidvertiser is quite popular among some webmasters. They provide contextual ads on your site and pay per click. The minimum payment is only $10 (paid via PayPal).
It is suggested that you use Bidvertiser as an alternative to one of the other programs.
Axill Publisher Network
Axill does not have any contextual ad program but has a large number of CPA offers. The USP for Axill is that they pay everyday. This could be an useful network to join if you have the right kind of traffic.
AdBrite
AdBrite is offering text ads and interstitial ads (pop-unders). They accept most of the websites and in general the price-level for publishing ads is the webmasters decision.