I used to think a folding keyboard for my smartphone was a necessity because I imagined doing all sorts of things on my old Treo -- revise Word documents and Excel spreadsheets, balance my checking account, write elaborate emails with attachments -- without anyone knowing I wasn't at my computer. Little did I know then that trying to do real work on a palm device on a regular basis would kill my eyes and make me bitter. These days, I rarely do any work on my phone that requires typing, beyond sending one-line replies to emails.

Still, there are those times (for instance, when I'm on a plane and we're two hours delayed in taking off), when a functional keyboard would be useful. I want one that I can carry in my purse (I want to carry everything in my purse). The Freedom Mini Duo Keyboard from Proporta.com ($69.95) has a full Qwerty keyboard, but is described as being just a little bigger than a credit card when folded up. It provides two modes, SPP (Serial Port Profile) and HID (Human Interface Device), so is compatible with Blackberrys, smartphones, and other Bluetooth-enabled devices, as well as devices using HID technology. Specific compatibility information is available on the site.

Weighing in at just 3 ounces, it provides 9 hours of continuous use battery life, or 45 hours of standby time (charges through USB cable).