I've been searching the internet for phone service providers for watch phones but it's hardly mentioned. I keep Googling but all I get are cell phone service providers, mentioned Consumer Watch. AT&T services only one watch phone which costs $300 and find MANY on-line for under $100. Even C/NET has only one old article on a smartwatch but NOTHING about watch phones. So I don't know what choices I really have. Where can I find a way to compare all plans that COVER watch phones?Not likely you will find what your want.
You are dither in North America or the UK. -Right? If so, you will find little.
At this time, Watch Phones are the rage in South Korea.
One example:
http://www.alibaba.com/countrysearch/KR/watch-phone.html
So it would seem that you have to live someplace where technology is more up to date. Perhaps that will change soon.



In theory a watch phone is just a regular cellphone in a different case, therefore any plan that works on an unlocked handset should work on a watch phone. Are you sure you are meaning a watch phone though as these are very uncommon and not popular at all.

Nowadays the real trend is with smart watches which would connect to a regular cellphone over Bluetooth therefore eliminating the need to have a separate plan for the watch itself.camerongray is right. The point I was trying g to make is that it matters where you buy and use it. The US, the UK , Japan and Asia all have desperate cell systems.
A watch phone does not have a case large enough to hold an effective antenna. So it will only work at close range to a cell or a Bluetooth repeater.

Here is a general GUIDE:

Smartwatch Buying Guide: 8 Things You Need to Know

Quote

The battle for your wrist is on. From big names like Samsung and Sony to upstarts like Pebble and Martian, more than a dozen companies are creating smartwatches to serve as your smartphone companion. While features and design vary, the main appeal of a smartwatch is to deliver notifications to your wrist (including calls, texts, email and social UPDATES), so you can decide whether it's worth whipping out your phone to respond. In other words, smartwatches can save you time — but there's a lot more to this emerging category. ...