That depends on which variety of rim. Some tires may go one rim easily, and be a beast on another. I would suggest, and did myself, getting a Kool Stop tire-jack - or a VAR super-tyre tool. Either of these will give one the upper-hand when mounting difficult tires. One side of these slide onto the rim on one side, and grab the tire underneath the opposite side. Then it's simply a matter of pulling the tool back - leveraging the bead up and over the rim and seating it in the rim.

The Kool Stop is rather large to carry and should be an in-home/shop tool:

http://www.jensonusa.com/store/produ...e.aspx?sc=FRGL

While the VAR is small enough to fit in a seat-bag or pant's pocket:

http://cgi.ebay.com/VAR-Super-Tyre-T...13125009r29737

Armed with one of these, you'll be free to continue your pursuit of a full Kevlar-belted tire. Regardless of how much of a bear they can be to successfully mount on a rim with conventional tire-levers/thumbs.