Sometimes, the future just sneaks up on us.

For years now, we’ve heard about the promise of true “mobile TV.” Predictions of explosive growth in video content and capabilities have been bandied about since the current generation of network technologies were rolled out in the first half of this decade. And the major American carriers like to tempt us with advertising suggesting our favorite television programs are available, anywhere.

But is mobile TV really here, or not? There seems to be significant confusion in the consumer market when it comes to some of the video options available today (versus options which may be available as soon as 2008). What exactly is “mobile TV”? Is it the same thing as “streaming video”? What kinds of things can I watch on my cell phone?

First, a quick explanation of the different services already out there. Many of the newer cell phone models in stores these days offer some degree of mobile television; the handsets themselves have become powerful enough to deliver relatively high-quality video content (albeit, on a tiny screen). The faster processors and high resolution screens present in today’s cell phones make viewing video a reality. The central hurdle some carriers are attempting to overcome — in the United States, at least — lies in network capacity.

As it stands now, the three largest carriers in America offer some form of mobile TV, most of which is pre-packaged. The 3G data networks that stream data to our phones are great for surfing the Internet, but if thousands of people all want to watch a live television event, the network would become bogged down. Each request for the program is handled individually, and, for now, only Sprint’s EV-DO network is set up to deliver live broadcast programming.

As mobile TV takes off, we can expect to see changes in the way content is delivered to our phones. The most likely solution is a “one-to-many” paradigm which echoes traditional broadcast TV; rather than sending unique data to each potential viewer, one central source would send out a single signal available to any cell phone within range.

That day is right around the corner. Today, however, most of the available video content in the United States comes in pre-recorded clips designed specifically for cell phones. When you’re shopping for a TV-capable cell phone, there are a few things to keep in mind. For starters, you’ll need to subscribe to your carrier’s mobile TV service. To do that, it helps to know what, exactly, is offered by each of the major carriers:

Sprint: SprintTV features a variety of broadcast channels over its EV-DO network, bundled within the Sprint Power Vision TV Pack. The service works well, and is augmented by a selection of packaged video clips from CNN, Fox Sports, and the NFL Network. Sprint offers a variety of pricing options, which is great for customizing your mobile TV plan.

Cingular/AT&T: The Cingular Video service is extremely effective in cities with 3G coverage. While there is no support for live TV, Cingular offers streaming clips from NBC, CNN and Fox News, and exclusive content from HBO.

Verizon: Verizon’s VCAST service is only $15 a month, and offers a myriad of video clips from popular channels like NBC, CNN and ESPN. VCAST also includes streaming cartoons and stand-up comedy, although none of their programming is broadcast live.

Since the mobile TV landscape is constantly evolving, it’s always a good idea to check a site like Wirefly.com or point.com for the latest specifics. As the cell phone industry keeps moving towards full multimedia integration, the services listed above can only grow in scope.