I'm currently monitoring a website auction where the owner has placed two Adsense units next to each other at the very top. To make matters worse, he also added a link unit above, and another large 728x90 banner below.
Another thing that I noticed was that the left Adsense unit appears to be an image ad unit.
I cannot find the reference, but I'm pretty sure I read somewhere that placing Adsense ads next to each other is against the TOS.
Anyone here who can confirm or refute that?