I did a bamboo floating floor in my vacation home...easy to install, wears very well and looks interesting. The floor was a snap together engineered floor system, whick I layed over a foam underlayment. The floor is really quiet underfoot also.
http://www.lumberliquidators.com/catalog/thumbnail.jsp?categoryId=13§ionId=3&subCategoryId=238&ref=By%20Category;274500014,By%20SubCategory;27460 0085
Currently Im doing some work on my primary home, Ill be installing cork flooring in this case.
http://www.lumberliquidators.com/catalog/thumbnail.jsp?categoryId=11§ionId=2&subCategoryId=92&ref=By%20Category;274500012,By%20SubCategory;27460 0068
I think I'm going to like the randomness of the cork. suppose to be very quiet, and has insulative properties also.