......gee it's frustrating at times!! I've been waiting an eternity to get rolling with Adwords, but my ad is still showing as "under review", hence no impressions. How can this be?? i've been waiting 7 weeks (without edit).........
Contact Google and just basically tell them waiting 7 weeks+ is not acceptable, and you're thinking about taking you're business to Yahoo.
your ad probably got "stuck" - don't ask me how. Delete the ad, then create the same ad again. This happened to me once and this was what support told me to do and it worked.