Oooh, that's one of the things I can't wait to do. Yes, I know it's not good for you and yes, it's something a lot of people probably never think of as something they can't do, but for me (and a lot of us, I'm sure) it IS a big deal.
Yay! I was looking at my skinny 6 year old the other day, & not only were her legs crossed, she had the top one twisted around & tucked behind her other ankle - pretzel girl!
(I got horrible varicose veins from working factory work right out of highschool. I spent 6 years working on a cement floor and even though I wasn't heavy then, it did do a ton of damage to my legs! Being out of that environment has helped repair them tremendously but I still get sore behind my knees if I strain them too much.)