What about media queries? (https://developer.mozilla.org/En/CSS/Media_queries)

pavel_lishin · on Feb 24, 2012

Those don't really affect the HTML that gets sent.

    # wget --user-agent="Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543a Safari/419.3" http://www.cnn.com/ -O cnn.mobile.html
    # wget http://www.cnn.com/ -O cnn.standard.html
    # ls -lhrt | grep cnn 
    -rw-r--r--    1 pavel  staff    29K Feb 24 13:12 cnn.mobile.html
    -rw-r--r--    1 pavel  staff   104K Feb 24 13:13 cnn.standard.html

I don't need 100K worth of stuff on BlackBerry 1.half's browser that can't render most of it.