As speculation over an Apple tablet began to take over the mobile conversation last year, many companies began developing their own alternatives. While a few have come to market, there are more in the pipeline than you'd expect. We've gotten actual confirmation of the Dell Mini 5 (or the Dell Streak 5), a 5-inch smartphone with a tablet feel. Just today, leaked photos of Dell's entire Streak tablet family surfaced on the web. The lineup includes never-before-seen 7-inch and 10-inch versions. Dell is covering their bases as far as size goes, and that might not be unreasonable. Some manufacturers, like Fusion Garage with the JooJoo, are betting on a larger form factor. But in this newly reinvigorated tablet market, no one knows quite how big these devices should be. We'll take a look at available and upcoming tablets, and help you decide.
 
Dell's leaked documents make it fairly clear that their Android-based tablet line will be called "Streak", but we're still a little unclear how the naming convention will work. The smallest member of that family is the one we have the most information about. The Streak  5 is sort of a hybrid as it's capacitive touchscreen is bigger than a traditional smartphone at 5 inches and 800x480 resolution, but it has 3G phone functionality. We usually think of a 4.3-inch phone like the HTC HD2 or EVO 4G to be at the upper limit of usability, and the Streak 5 might be a bit too big to hold to your ear. But it's unclear if that extra bit of screen real estate will give you a tablet-like experience.

There is a 5MP camera on the back, and a VGA camera on the front. In prototype devices, the Streak 5 seems to be running a skinned version of Android 1.6, but that is likely to change before release. The Dell leaked promotional materials appear to indicate the 5-inch tablet will have content partnerships with Amazon for Kindle and Amazon MP3 access. In most ways, this is being pushed as a tablet. It is expected to ship this summer. A 5-inch tablet might fit in your pocket (unless you wear skinny jeans), but Dell's other offerings won't.

The leak of the 7 and 10-inch Dell tablets show a clear intention to compete with the iPad. Even the overall design looks vaguely like the iPad, with the large flat bezel. It makes us wonder if the Streak 5 is in for a redesign to match its big brothers. The Streak 7 should be out late this year, and the Streak 10 will follow in 2011. From the leaked photos, we can definitely tell that the devices have widescreen displays, unlike the iPad. We can only assume these tablets will not have the unexpected phone functionality of the 5-inch version, but they may have 3G data. The larger Streaks are clearly in the not-pocketable category with the iPad.     

The iPad is using a 9.7-inch 1024x768 resolution 4:3 display. The JooJoo ups the ante with a 12-inch 1366x768 widescreen panel. Larger displays can give you a better experience at the expense of portability, but another thing to consider is the screen ratio. The iPad is 4:3 (like an older computer monitor) in order to be comfortable to hold vertically as well as horizontally. Indeed, holding the JooJoo with its sizable 12-inch display in portrait mode looks a bit awkward. Additionally, the JooJoo is basically running netbook internals, and weighs 2.4lbs, which makes using it a workout. That's almost a pound more than the ARM-based iPad at 1.5lbs, which already feels heavy after prolonged use. In the same boat as the JooJoo is the upcoming WePad. The specs are almost identical with an 11.6-inch widescreen display and Atom chipset. The Dell tablets may also suffer from this dilemma, but the slightly smaller size could help.

Archos has a number of tablets on the market as well. Coming in a variety of sizes (like the Dell Streaks), you should be able to find one to fit your needs, or pockets, if you choose to go this route. There is a 5-inch model that runs Android, as well as 7 and 9-inch versions that run a proprietary Linux build. Rumor has it Archos also plans to release a new line of tablets this summer from 3-inches all the way up to 10-inches. These are expected to be ARM-based devices, so weight shouldn't be much of a problem.

The HP Slate was shown off at CES2010 by none other than Steve Balmer, and is often cited as an alternative to the iPad. You're not going to see a lot of difference here from an iPad. The HP Slate will have a 8.9-inch display, but as it's running on an Atom CPU (like the JooJoo and WePad) we're worried it may end up a bit on the heavy side even with the smaller display. But some leaked documents indicate HP has worked hard to keep the weight down, as it's listed at 1.5lbs. That's the same as the iPad.

If you decide to take the plunge and get a tablet, the size is going to be an important factor. If you never want to use something because it's too big, or too small, or too heavy, there's no reason to have it. If you want a bigger screen, it's going to be heavier. Keep an eye on the weight before buying. Even the relatively light iPad can be uncomfortable to use for long periods without resting your arms. If a tablet needs to ride around in your bag all day, a larger tablet like the JooJoo or WePad might be too big and awkward. If you're considering a tablet purchase, how will the size figure into your decision?