Do you use css frameworks?

I would like to know if habrachelovechestvo css frameworks?
And if so, with what and, most importantly, why? Recommendations for use would also like to hear.

A small list of CSS frameworks (by curlybrace ):

Blueprint
Css-Framework.ru
WYM Style
A CSS Framework
Thestandardsguy
Jim wimpey
YUI Grids (Yahoo)
Taffy