Any program I've seen that handles JPG will allow you to crop and resize a picture.

I keep an old copy of MS PhotoEditor around just for simple tasks, although I have SnagIt, PhotoShop of Visio. As said above, there's plenty of free programs as well. I've used so many I don't even remember the names any more.

A good spot to go for free (legal) software in all categories is http://sourceforge.net/
In this case, you can try the Multimedia section.

Using Photoshop (a professional grade photo/graphics manipulation program) to crop and resize a picture works, but it's like using a MOAB (Mother Of All Bombs--daisycutter) to kill a mosquito.