The last time I changed my rear tire I used a hair dryer (I wrapped the tire with some trash bags so there was only one air inlet/outlet and pointed the hair dryer so that it forced warmer air to circulate through the tire). In the time it took me to take off the old tire, the new tire had warmed up (warm to the touch) and went on so easy that I didn't realize that I didn't use any lube until I was done. (I put on a sport touring tire [Pirelli Sport Demon]).
(Yes I decided to try it because it was a rainy day, but it worked much better than leaving it in the sun, but that may be because I live close to the coast)