I don't usually plug other businesses, but I would like to tell you guys about the cellular phone service that I switched to a few months ago. It's called Republic Wireless and unlimited calling, text and data service only costs $19.99 a month. (About $23 with tax) The reason they can offer service so cheaply is because, while you're at home, they route your phone calls through your internet connection via a wireless router. This saves them money. Once you leave home, the phone automatically switches over to the Sprint PCS network.
Now, this service isn't for everyone. It's for people who spend a majority of their day near a wifi connection whether it be at home or work. Also, the Android phones aren't cheap. However, the phone will pay for itself in savings within 6-7 months, then everything after that is just money in the bank. You should be able to save at least $400 a year off your current plan, maybe even more depending on your provider. Republic Wireless is a relatively new company and they are still working the bugs out; however, I have been using them for a few months now and so far I have been pleased. I have had a couple dropped calls in the last 2 months, but that's about it. There may still be a waiting period for their service but it's worth the wait.
Here is a link to their website
http://www.republicwireless.com/