rogerd - 9:47 pm on May 22, 2004 (gmt 0)

If you can't locate solid sponsors, you can always test AdSense - the general feeling is that AdSense generates better revenue than conventional banners, though your situation may vary.

Yet another thought are affiliate links related to your forum topics. You could run text links or banners, and the ads could be general or even related to page content if you can integrate a feed.