Hey, same here.. Under 18 /lol
Yeah, Adsense, adbrite, etc. needs you to have that requirement (Just like what i mentioned in my site).
But in fact i'm not too concern about it.. We can do a lot of thing from now beside PPC..
We can built our niche and our site first.. And if we have a site with big traffic, many will ask u to add their ads or links in ur page for some bucks in return..