For walking around the bar, when I use any kind of mat (most of my effects are done in my hands, or in a spectator's hands), I use a regular mouse pad that I got at Walmart for $3.00. It's a big yellow smiley face, about 8 1/2 inches in diameter. For close up effects that require a bit more room, I have a second smiley face mouse pad rolled up in my bag. People like the big smileys, and the bright yellows and oranges, in a dark bar, make for a bright and easy-to-see surface.
Oh yeah, I wrote "Thank You!" at the bottom of both pads, very neatly with a sharpie, which is a subtle and professional way of saying "tips are welcome!"
<><> SunDragon Magic <><>
"Question Reality... Create Illussions"