The Freedom Pro is available under a bazillion different brands and just as many prices. There are three or four keyboard layouts aimed at PC and phone users. I've got a PC-layout version which I use with a tablet, a phone and a media centre. It works very well, wakes very quickly and folds in two. Battery life is a couple of weeks. There's a little pop-out stand to support cellphones. I think it was around $35, around a third of the price of the identical one next to it in the shop.
A better keyboard in terms of touch, but nothing like as portable, is the Microsoft Mobile 6000.
I've used a couple of very small keyboards and ended up with the folding one as a better compromise.