I always mount my large prints to protect them. It is easier to frame a mounted print and if you don't get the chance to frame it right away, it's less likely to get wrinkled or torn. Mounting a large print will also prevent it from warping inside the frame over time. Aside from protection, one of the perks to mounting a print of any size to a sturdy material like masonite, is that it gives you a few more options for creatively displaying your photograph. One of the easiest ways to display a mounted print is to place it in a decorative easel.
Easels are great for displaying both framed and mounted prints. I found this small easel at Gordman's here in Rockford and I paid less than $3 for it! I ordered the 8×10 print on 1/8" masonite from my lab. Masonite, matboard and styrene are not officially intended for anything other than framing: if you bump the corner hard enough it will dent, and I have noticed single weight styrene will warp slightly over the course of time if it is not supported. But, for a small print that you want to rotate out every so often, it's more economical than ordering a standout print.
You can order mounted prints from MPIX.com. Frame them, place them in an easel, decorate the edges with ribbon, etc. Get creative, get those digital images off the computer and enjoy your photographs!