I am now trying out ViralBlogAds (afflink) which also is a 125×125 ad system, you can also use 468×60. Its still in pre-launch but you can add 3 free ads which will be displayed in free spots.
As a participant in the ViralBlogAds pre-launch contest, you must add your website to our database in order to display the publisher code on your site. Eligible publishers will then be selected at random as winners of our selection of prizes. The contest will begin on September 1st.
It took me 30 seconds to sign up, it looks good and it has several tools for checking performance on ads. It it Paypal based and you can withdraw money when balance is $25. Balance will be updated each 14th day, they have a function to prevent click-fraud, which is very nice.
I look forward to check it out. Btw you can approve and disapprove incoming ads.