The majority of my posts are obviously from my laptop. But I have posted and browsed from my (school's) iPad 2, and interestingly enough from my Wii. I would try to do it from my DSi, but it doesn't like the way I have my router and modem set up at the moment, so it can't connect to the internet.
I think I used AG on my Wii a year or so back, irritatingly annoying to post from, especially if you hit the wrong key and them when you hit another wrong key trying to get backspace. Usually ends up in me ragequitting.
I have posted from my I-pod touch and my computer... I lost my I-pod so mainly my computer. Strangely enough I have never posted from anyone's computer but my own.