Just in time when I was looking for something like this... it can be used to target your ads acc. to geographic location of your site visitors and can be used to sell, schedule your ad inventory etc. The only problem as of now is that its open by invitation only. Nonetheless you can apply for it and if they find your site suitable they might invite you in beta program. Read the full details here
Abhik, can you send me some useful information how to start with OpenX and Adsense. I have installed it successfully and created some banners and campaigns but still it is not so clear how to integrate al this things. 10x
There is one similar open source tool from openads.org but generally G 's products are much better so will wait for this one.