The Dell Streak is a big phone

On Friday, the Dell Streak tablet makes its long-awaited debut, selling for $550, or $300 with a two year voice and data contract from AT&T.

The Streak's 5-inch screen is being sold as an advantage over iPhone's 9.5-inch screen. Dell pitches the Streak as the "sweet spot," able to act like either a tablet or a smartphone. Of course, being a jack of all trades has a downside, and the Dell Streak is likely to falter in as many areas as it excels. I haven't tried the Streak yet, but I can imagine some situations where the device would be useful, and others where having either a smartphone or larger tablet would make life easier.

The Streak will obviously be more portable and easier to hold than a large-screen tablet. Imagine pressing an iPad to your ear or holding up a tablet the size of a dinner plate to record video and you'll understand why Dell's smaller frame could make makes sense as a camera or a phone.

Then again, pressing a 5-inch display to your head might look a little silly next to today's slick smartphones, but at least it can be done.

By sacrificing size, the Streak will give up the ability to be a good e-reader. You'll still be able to read e-books on the device -- Android apps are available for Kindle, Nook, Borders and Kobo -- but the experience won't be like holding a book. In general, I think the Streak borrows more qualities from smartphones than tablets, especially considering that AT&T will sell voice plans with the device.

Why not just use a smartphone, then? Because smartphones, even the larger ones, run out of screen too easily. The Dell Streak videos I've seen show a good use of side bars and pop-up menus, giving you more control without taking the focus off what you're doing. And with the Android operating system's use of widgets, there's going to be a lot of action on the home screen that wouldn't be possible on a smartphone.

Which brings me to one more concession: The larger the screen, the greater the inconvenience when lugging the device around. Dell says the Streak is pocket-friendly, but it's probably better for pocketbooks.