I've been writing about designing for mobile for years now, but it seems like only in the last couple years has it become really possible to do real work on a mobile device. I have used a laptop for years (I'm writing this poll while at my son's swim lessons, for example) and I've had an iPad since the first version came out years ago. And, being stubborn, I've done a lot of work on my iPad. It's still not possible for me to do everything on my iPad because some of the tools I have to use use Flash, but I can do most of my writing on it and manage most portions of my sites with it. I don't like using my iPhone because the screen is so much smaller, but in a pinch I have written notes on that as well as corrected some typos on my sites using the phone.
Do you do work on a mobile device? What types of things do you do? What kind of mobile device do you have?