Google Ad Manager

Google Ad Manager, its a new Service from Google and still in Beta stage. This is Invitation based and you can not create an account unless you get an invitation from others who are using this or you can apply for an invitation from Google Here.
Its just like other Ad Management system (Ad Server) like OpenX or AsRep but you don’t have to worry about the critical installation process of them. Google Ad Manager is equipped with all the necessary features which you will need to manage the ads on your site. It also supports managing multiple sites from a single account.
You can also sell your adspace directly to any advertiser. What they have to do is click on the link, and they will be redirected to the Google Ad Manager and there they will pay, and give their site details. The whole process is automatic and takes only 5 minutes or so.
Not only that, you can also target many things like Geographical Source, Browser, Operating System and many more. You can target them individually for each of your sites and they are independent. Say, if you want to show your FireFox referral ad for US visitors who is using Internet Explorer, this is the way. Cool, right?
You can also track the clicks on ads, IP Address of the clicker, Time and date of Click, Clicked Ad Unit and many more. The will be saved as log and you can use this log for anything you want like reporting suspicious activity, Click Bombing and others to the respective Ad Network.
You can also fill the unsold space with ads from any ad network like adsense, YPN, MSN AdCenter, AdBrite, Chitika.. any or just use them as the advertisement.
If you are a professional who manages the ads for you company, you can set permissions for each of your office groups like Administrators, Sales Representative, Managers etc. Thus, only one account will serve for all.
Google probably will integrate this wonderful tool with adsense in near future when it gets open to all.