Streaming video is awesome, but of course it requires you to have a robust broadband connection. Once you're outside your home or business, that's an iffy proposition. WiFi hotspots aren't always available, and even when they are, they're often over-shared so connection quality is too low for video. Wireless 3G or 4G cards are better, but their relatively low data caps seriously crimps viewing. And if you're on a plane, forget streaming entirely, Gogo doesn't cut it at all.

These real-world mobile limitations mean downloading video in advance, rather than streaming it, is the key to on the go viewing. This has been one of the value props of iTunes, Amazon and other services. But the reality is that lots of great content is already sitting on your DVR (and if you're like me, 30K feet is when I most often actually have time to watch any of it). Further, you've already paid a lot of great content with your pay-TV subscription. The problem is that DVR video has been pretty much locked in your home, without an easy way to take it with you. All of above problems are solved with TiVo's new "Stream" companion device, which TiVo announced last week.

As Jeff Klugman, SVP of Products at TiVo, explains and demos for me in the below video interview at last week's Cable Show, Stream will allow iPad and iPhone users of the TiVo app to access, and with one click, download programs from their TiVo DVR. Stream transcodes the video and delivers it to the device in one-fourth the duration of the program, meaning a one-hour episode transfers in about 15 minutes. Once downloaded, the video plays in 720p quality, taking up about 1gig of local storage per hour. Imagine recording Sun afternoon's game and bringing it with you on the flight that night, or loading up the iPad for the kids before your next road trip. Pretty appealing, huh?

The new iOS downloading feature is a huge step forward from TiVo's current desktop "TiVoToGo" process, which requires downloading first to computers where it is transcoded before viewing. Moreover, Stream directly addresses consumers' embrace of the iPad for video viewing. It also saves money on redundantly buying programs on iTunes and Amazon just for portability when they're already recorded.

There is a little fine print involved. First, only content marked by pay-TV operators as "copy freely," or not marked at all, will be downloadable. That rules out all shows from HBO and other premium channels, but does rule in all broadcast programs. Jim Denney at TiVo explained that how programs are marked varies widely by pay-TV operator and even within them. However, the same copy restrictions have applied to TiVoToGo, and have resulted in few complaints, so Jim is confident that Stream downloading should be pretty flexible.

You'll also need to buy a Stream device for which pricing has not yet been revealed, but is likely to be in the $100 range, when released later in the summer. And of course you'll need to have a TiVo in the first place, which, as always can be bought at retail, or accessed via the set-top boxes from a handful of cable operators (Comcast included, which is how I get my TiVo service). Then there's the TiVo service fee, which is around $15/mo.

In addition to the downloading feature for on the go viewing, Stream will also allow users in their homes to stream both live and recorded programs to iOS devices, a handy feature that obviates the need to pay for additional set-top boxes.

I'm very eager to get my hands on Stream for the iPad downloading capability. I think it's a killer app for the iPad, adding significant new value to the TiVo proposition vs. plain vanilla DVR alternatives. Someday there may be plentiful bandwidth so we can all have robust and affordable broadband connections to stream video wherever we are. In the meantime though, downloading video has a lot of runway to provide real value and TiVo's stream looks likely to hit the mark perfectly.