Actually, even cheaper is CallPlus, which is as low as $10 every 90 days. I use CallPlus as a secondary carrier, as their phones work in rural areas (analog capability) where my T-Mobile and Sprint phones do not. This is an unpublished fact, but as long as you use at least one minute of airtime per month, that $10 CallPlus refill card will never expire! I haven't refilled my CallPlus airtime since last October. Only drawback is when you're roaming off the old AT&T digital network, now known as "Cingular Blue," you're charged 4x the per-minute rate. But you can use any old, deactivated AT&T TDMA phone with CallPlus (you can find one very cheaply off eBay) and as long as the phone includes analog, you'll have coverage wth CallPlus just about anywhere there's cell service.