i always reduced the number of workspaces in ubuntu to 1 until i got my hands on a macbook pro and figured out the gestures. it's incredibly easy to manage your opened apps especially on small displays. if you assign your programs to run on specific workspaces like <<plantain>> said you might be surprised. i know i was. and it only took me a couple of days to get used to them.
the biggest problem i see is the interface. gestures on mac saves you a lot of trouble as switching a workspace is only a three finger swipe. so, on linux, no gestures, this means keybinds -- god! i hate keybinds (i work on win, mac and linux and i get confused sometimes :)).
maybe a combo of mouse gesture + click/keypress could ease our lives in linux.