No Follow On Tags With Less Than 3 Posts

I’ve noticed that many of my tag pages only have one post. This makes them virtually useless on all accounts to users, search engines, etc.

I see that in the WP admin that wordpress keeps track of the # of posts for each tag and I was hoping that variable was available on the_loop and single.php. I’d love to either entirely remove these tags UNTIL they are mature enough to be of some value or at least no_follow them.

Is there any quick and easy functionality for this?

Thanks!

Brandon