Unfortunately not. I flew out of LAX a couple of years ago and tried to claim tax back in the airport like I have done in Canada in the past and was told (quite rudely) that there are no facilities in USA airports for this and I would have to do it when I got home.
To be honest I didn't go to the trouble when I got back for the sake of $65 approx; still don't know how either.
Don't know if you are aware, you can only claim tax back on goods you bring out of the country and they usually have to be over a certain amount ($200 in Canada if I remember correctly). In other words you cannot claim back tax for things like accommodation, food, car hire etc but you can if you are bringing back something like a digital camera for example.