activeco - 11:18 pm on Mar 27, 2007 (gmt 0) Anything else (white hat) is OK.
Unless you run adsense, there is no reason to worry.
Every other business is a business, but Adsense cannot be business in Google's eyes. So if you have multiple domains 'doing' Adsense, you can be "smart" downpriced and even penalized.
Anything else (white hat) is OK.