square_cat - 10:37 am on Jun 9, 2008 (gmt 0)

If you're happy to run with low traffic then look for the more niche long phrases (long tail of search if you will...). You should be able to get chjeaper clicks by using more targetted keyword phrases rather than the higher traffic geenric terms.
This will obviosuly bring less traffic but should keep you CPC lower (and in theory increase your conversion rates)