Summary: If you want a very thin keyboard with almost full-sized keys, silent operation, a spill resistant covering, handy iOS-specific hotkeys and decent battery life, check out the Logitech Keys-To-Go.
Dimensions: 5.39" by 9.53" by 0.24" That's right, it's only a quarter-inch thick.
Weight: 6.35 ounces
Battery Life: Logitech states that the battery will last for three months on a full charge, with approximately two hours use per day. Of course that is an estimate. Full charge time is 2.5 hours and Logitech state that each minute of charging provides approximately an hour of use.
Despite it's diminutive size, most of the keys feel full-sized or almost full-sized. Put it this way: I'm used to typing on a large ergonomic PC keyboard, and it only took me a minute or two to get used to the Keys-To-Go. If you're used to springy clicky keys, it may take you awhile to get used to keys that don't travel nearly as far. I'm a fast touch typist, and have no trouble going full speed on the Keys-to-Go. After using it for awhile, the full-size PC keyboard feels strange and clunky in comparison.
The Keys-To-Go is not waterproof, but it is definitely water resistant. the keyboard is covered fully by what Logitech calls FabricSkin, a protective textured membrane.
Any liquid spills or crumbs can be wiped away with a damp cloth. The only part of this keyboard which should not get wet is the top right-hand-side edge, which contains the power switch and mini-USB charging port.
The Keys-To-Go can work with any device, but it is optimized for use with iOS devices. From left to right, it's top row of 14 keys perform the following functions:
1. Home screen,
2. App Switcher
4. switch keyboard language,
5. show/hide virtual keyboard,
6. take a screen shot,
7. previous track
9. Next track,
11. volume down
12. volume up
13. Bluetooth connect/pairing
14. battery status
Heading left from Spacebar, the four bottom row keys are: CMD, ALT, CTRL, and FN.
Right from Spacebar, CMD and ALT are duplicated.
Other iOS shortcut keys:
Fn + X = Cut
Fn + C = Copy
Fn + V = Paste
Fn + Left cursor = Select left word by word
Fn + Right cursor = Select right word by word
I have not had to re-pair the Keys-To-Go with my iPhone in weeks. As soon as you pair once by turning Bluetooth on in iOS, pressing the 2nd from the right key on the top row to pair, and tapping the Keys-To-Go in the list of detected devices, you're done. Your iOS device should simply recognize and use Keys-To-Go as soon as you move the power switch to On, as long as Bluetooth is enabled in Settings of course.
I first tried and returned the Logitech K480 keyboard. It was substancially thicker, louder, not protected by a membrane, and I couldn't get it to pair with my phone.
Price: The Keys-To-Go is about $70 US at the usual places - Apple online store, Amazon, Wal-Mart, Best Buy etc.