I treat live games and online games as two completely separate games, in my opinion they are worlds apart.
Locally we have some really strong players that play live that suck online and vice-versa. Of course there are those that suck at both and those that are strong players in both disciplines.
I find that in live games there is much more opportunity to play the player and it is easier to remember who got burned a few hands earlier and maybe slightly on tilt, I have to admit I am not an expert on getting tells but there is a LOT more information presented in a live game than in an online game that you can use to your advantage.
Of course with online games you can still pick up some information, for instance, the speed people take to call or bet, also if you are using software such as Holdem Manager you can identify players weaknesses (Or if you are really good, do it without the software) One thing I find though with online games and I am sure most people will agree, is that the hand range is much broader and some people will play hands safe in the knowledge they do not have to deal with a stare-down pre-action or get the communal table look of "WTF you doing playing that trash!"
So to sum it up
Live Games = Square Peg
Online Games = Round Hole