I've put Typekit on my Bueno installation and added CSS editing and a few others things too (WordPress.com is such a bargain it seems silly not to). I used Panos's excellent instructions here to do this - http://wpbtips.wordpress.com/2010/05/30/improving-bueno-via-typekit/
There is one thing that still puzzles me - and Panos can't see the answer either. Is there a way to get a Typekit font to affect the dropdown menus? We've both looked at the CSS and can't figure out a way to do this. Any suggestions please? Panos suggested halluke might know if he has the time