I have but I stew them a bit first and vacuum seal. I use them in any recipe that calls for stewed tomatoes, like spaghetti sauce. I also dry them, but they don't last as long unless I vacuum seal them and freeze them.
I have never tried just freezing them, but if you can keep them from getting freezer burned, they should be fine for cooking.
A good vacuum sealer is worth it for keeping things longer. Costco has a nice one. This is one item I would not skimp on quality.