Even if you're comfortable with the iPad 2's on-screen keyboard and can happily tap out a status update or quick email, you might not want to use it for tasks like writing a lengthy report. One option is to ditch the tablet for a full-fledged laptop -- but it might be just as easy to add a wireless Bluetooth keyboard to the iPad.

The ideal wireless keyboard would offer a full-keyboard typing feel while still being light and compact, making it easy to carry. Unfortunately, that's a little like asking for a 25-in. monitor with brilliant display, light weight and low cost -- chances are, you'll need to compromise somewhere. Which features you're willing to budge on depends on personal preference, but in any case, it makes little sense to get an iPad keyboard that's no better than the on-screen version or that's so bulky that it makes travel with the iPad no better than lugging a laptop.

After that, your preferences will likely vary considerably depending on whether you are an accomplished touch typist or use just a couple of fingers to pound the keys.

I got my hands on five portable wireless keyboards for the iPad 2, judging them on several factors likely to be important to a mobile user.

For mobility, I considered weight, form factor and how easy it was to carry around (all but one of these keyboards fit around the iPad 2 to form a single unit; only Apple's wireless keyboard remains a separate unit).

With keyboard function, I judged how the keys felt and how they responded. And, in ergonomics, I considered how it felt to actually use the system. Did it feel cramped? Could I use it in a comfortable position?

With that in mind, here's a rundown of five portable Bluetooth keyboards for the iPad 2. (Note: A roundup of keyboards for Android-based tablets is coming soon.)

At first glance, the Apple Wireless Keyboard doesn't seem like much of a mobile option. At 11.1 in., it's quite a bit longer than the iPad, increasing the traveling form factor significantly.

However, the keyboard is lighter than it looks. With an affordable keyboard case (I like the $15 model from WaterFeild Design), I can easily pop it into my backpack when on the road. Two pieces can sometimes even be a plus while traveling, allowing you to use the iPad as a conventional tablet while in the plane, with keyboard packed away, and then more like a laptop once you reach your hotel.

Setup is a breeze, and the ergonomics are excellent. There's a reason this feels close to a standard keyboard: Itis one (except that it's missing the number pad and three normally unused function keys). Keys are spaced for conventional touch typing and are responsive to the touch: not too stiff to require pounding, but not so soft as to produce letters while fingers are just resting.

Note that this keyboard is powered by two AA batteries, while the other keyboards reviewed here recharge via a USB connection. This is also the only one among the group that was not designed specifically for use with an iPad.

However, if you're looking for something that lets you use the iPad for more serious content creation while you're home -- or if you're traveling where size isn't an issue (for example, if you're driving) and you're willing to travel with two pieces instead of one -- this is a good choice.

Apple Wireless Keyboard from Apple

Price: $69.00

Dimensions/Weight: 12.8 x 7.3 x 1.4 in./ 0.7 lb.

Mobility: Good

Keyboard function: Excellent

Keyboard ergonomics: Excellent

Best for: Touch typists who are less concerned about packing efficiency than typing comfort.