I've often said it's not the price of smartphones that bothers me, it's the monthly fee you have to pay for service.

AT&T and Verizon, for example, charge $59.99 per month for 900-minute plans--not including the obligatory data plan for your iPhone or Android phone. And if you're a serious gabber, the unlimited voice plans will run you $69.99 monthly.

Wouldn't it be great if you could switch to the cheapest available voice plan, without giving up a single minute of talk time? Thanks to a couple amazing apps, you can.
MagicJack for iOS and NetTalk for Android and iOS offer totally free calls to anywhere in the U.S. and Canada--landlines and cell phones included.

Contrast that with apps like Skype and TruPhone, which charge a few cents per minute for calls to regular phones.

You've probably heard of infomercial staple MagicJack; it's the gadget that plugs into your PC to provide unlimited local and long-distance calls. The eponymous app brings that same basic functionality to your iPhone (or even your iPod Touch or iPad), allowing you to make calls over Wi-Fi or 3G--thereby saving your pricey voice minutes.

And if NetTalk sounds familiar, it's because I reviewed the MagicJack-like NetTalk Duo just a few weeks ago. This company offers its own free-calls app for both Android and iPhone.

Okay, let's talk about the strings attached. Surprise! There aren't any. Not major ones, anyway. You don't need to own a MagicJack or NetTalk Duo to use the apps. You do need to sign up for an account with either service, but that's free and easy.

There are, however, a couple limitations, mostly related to inbound calls. The NetTalk app doesn't allow them, period. And with MagicJack, anyone wishing to call you has to dial a special number, then input a 10-digit code. (One exception: if you do own a MagicJack device, its phone number can be used to receive calls on your iPhone.)

Also, NetTalk limits you to 30-minute conversations. But on the plus side, it can record calls and even host conference calls--two features the MagicJack app lacks. On the other hand, MagicJack places no limits on call length.

All this is small potatoes, in my humble opinion. The apps are free and the calls are free, and they don't consume any of your minutes. (They do, however, consume data—something to consider if you're on a fixed data plan.) I recommend test-driving one or both, then dropping to a cheaper voice plan. You stand to save $20-30 per month!

While we're on the subject of saving money on your smartphone, be sure to check out my cheap alternatives to the pricey AT&T unlimited texting plan.

Self-proclaimed cheapskate Rick Broida has been a technology writer for over 20 years. He has authored over a dozen books, including, most recently, "How to Do Everything: Palm Pre." Currently he writes the Cheapskate blog.