BoK, I have a nice experience of running adsense at forums.

Links block that you have at top of the page works a way better at bottom, somewhere between posts and Tags block. It nicely works for guest users, that find forum at google, read some topic that they find, scrolling down the page and AFTER reading, they got an ads (usually) related to their search. so they click. the click ratio for bottom links block can be 2-4 times larger than top links block.

also adsense have a nice side effect like better indexing by google, though G have different bot that crawl the pages to check what kind of content thay have to show relevant ads, overall indexing increase too...