Honestly,
I think admob will end up being better as an ad-client for mobile phones because it serves ads with mobile sites...
When you start talking about adsense or adcenter or yahoo publisher network or all these other websites, they'll serve full websites.... That aren't necessarily designed for mobile phones. This may end up hurting your clicks in the long run as your users/players will know after some time that the ads are to irrelevant websites.
As for the clicks that didn't go through, i'm not sure what's going on there but be very careful! If they track the clicks back to you in some way (say you log onto your account from your phone and that's where you clicked), they'll suspend or ban your account.
For some companies (adcenter) you don't even have to do that!!!!!!
Speaking of which, Brian; have you heard back from adcenter at all? I never got a reply from that lady.
Lastly,
I've been thinking of writing a small library to contain the high scores page layout. I would make it universal so that you can call the activity and send specific data to it and it would submit to the server or however. I think it would be neat to have a universal high scores system. I'm thinking of having this run off of my server (if it can hold it), and do some sort of profit-sharing for developers who'd like to use it. The benefits of this is so that you don't have to buy your own server, don't have to write your own scripts and databases to hold all of the high scores, and mess with all that crap. I've spent countless (literally, 100's) bettering the system and this would be kept up and updated since I'm constantly trying to make the scoring system better for my players.
I would set up some sort of profit sharing with devs who use the high score system supplied by me. Maybe 70% you, 30% me. That 30% would pay for everything like the server, maintenance and all.
I don't know. It's definitely not something I'd expect to make any real money off of, but I'd like to at least build a brand and help other devs who don't really need to re-invent the wheel. Let me know if you guys would be interested in it before I put all the time in making it open for all

Without God, I would not have ANY skills.