I recently got it into my head that I should be a writer. My absolute favorite keyboard for doing large amounts of typing is the ubiquitous Lenovo ThinkPad keyboard. I would even consider it the gold standard in portable keyboard design. Of course, carrying a laptop with me wherever I go is less than Ideal.
That's when I discovered the iClever Foldable Bluetooth Keyboard. Before setting out on my daily trek I simply stick it in my back pocket. If I have spare time I can stop at a coffee shop and work on a story. However, I do my best writing somewhere between beer #1 and beer #2. Stopping at a pub during my walk home from work is the perfect chance for me to bang out some prose. Instead of a complete laptop I simply use Google Docs on my phone.
However, what I've described so far is my love of the form factor, not the keyboard itself. The keys always provide tactile feedback when pressed, but they will register either 0, 1, or 2 key-presses each time. With my beloved Lenovo keyboard my typing speed is around 80 words per minute with 100% accuracy. After a few weeks with the iClever my WPM is at 50 and my accuracy is 80%. The key locations are subtly off, especially when using symbol keys, modifiers, and the frustrating backspace.
If you're looking for a pocket-friendly keyboard for writing simple text, then this keyboard is for you. If you are a programmer intent on writing code, I would look elsewhere.
As it turns out, Lenovo does make a ThinkPad Compact Bluetooth Keyboard with TrackPoint keyboard. Unfortunately it can't be folded up like the iClever keyboard. It also doesn't support the ability to swap the Fn and Ctrl keys like the laptop BIOS supports. It costs about twice as much as the iClever, too.
Update: I did end up buying the ThinkPad keyboard. While it is a treat to type on, it can be a bit difficult to pair with a device, especially if you ever swap between devices. The keyboard is great however there aren't many situations where it's the ideal keyboard to type on. Since it's almost as large as a laptop I find that simply bringing a small laptop is more practical.