Bluetooth and USB keyboards work well, though I have found it is a total pain to tote them around with the tablet- may as well bring along my laptop. The device will also recognize wireless keyboards and mice with those little USB receivers.
My favorite keyboard (I have tried ALL of them) is by far Thumb Keyboard by Beansoft. It has a killer split keyboard that works great.
I would prefer a case type keyboard cost then I can really setup a mini office from anywhe,. I like the flexability the tablet has. If I can type 40 words a minute I'll be happy too. Stoked actually :-)
Great price! Small form factor and Android shortcut keys make this a must have for tablet users. I use mine along with a USB connected mouse and that makes my tablet very PC like in functionality. When not using the BT keyboard I use SwiftKey for tablets. Great word prediction and you can change the keyboard layout so that the key group closer to your thumbs when in landscape mode. Great vKeyboard!