There are quite a few jQueryMobile functionalities that rely solely on the CSS fole, eg. the grids. You won't get the interactions, but all the buttons looks, shapes and colors are totally useful without the JS.
Still - depends on your expectations.
And when using it like that you need to understand a bit how JQM works to know the classes and html structure that's expected, because some of these are generated by javascript.
[kind of digression]
But maybe you just dislike how big jquerymobile is?
Then you probably want to use: http://jquerymobile.com/download-builder/ to get only stuff you need, and also use tte themeroller here: http://jquerymobile.com/themeroller/index.php to create only one theme (global) and remove other themes (A,B,C)
That's how you get it a lot smaller.