This is the biggest reason that I haven't dropped my texting plan altogether. I use Google Voice for my primary SMS # (GV SMS Extension, and biteSMS to integrate w/ my iPhone), except for those times when I need to send or receive an MMS (mostly to or from my wife who doesn't have a smart phone). I use about 6 or 7 SMS/MMS per month, and I know it would be cheaper to pay per message, but I like the security cushion of having up to 200 at a flat rate. I've thought about dropping it, but if I find out that I want an SMS plan again I'd have to jump up to the next plan.