If you have a moderately static IP address, write some PHP to insert the following line into your AdSense ad variables whenever it detects your IP address:
google_adtest='on';
A Google tech sent that to me and told me to use it, so it's totally legit.
No, he's asking how to prevent the ads he sees while he's building/testing a site from clouding his stats. Banned was just an unfortunate use of words...