In my researching smartphone sites I've been unimpressed with the ui for menu access, particularly large sites that require a lot of horizontal scrolling.  Why aren't there any floating '+' sidebar icons to access a menu while mid-page?  I generally hate floaters but I think I hate slot-machine scrolling back to the top even more.

Not a sidebar, but floating header.

http://azadcreative.com/demo/responsive-nav/

This seemed slightly unresponsive on the desktop last night (chrome, xp sp3)

Not bad on the iPad.  Normally I hate floating navigation do-hickeys but this is much better than most.

I can break that on dolphin by hitting the bottom of the page then scrolling up again.  Its good though - pretty usable