Mine is pretty lame. Basically tape a couple posters up to the wall, put some posters on a stool or table and keep change in my pocket. The key is the bar I usually sell them at has a directional light right next to where I sell them that I point at my posters taped to the wall. Hoping to get a frame some day to make them look more awesome but I keep putting that off.
Honest answer - For the larger posters, get the plastic sleeves with cardboard backing (more on that here: http://www.gigposters.com/forums/any...d-backing.html). Get a box of of appropriate size, cut it down so the posters can be viewed while flipping thru the box. These boxes can be set on the ground next to the table, and the table can have all the little prints and small stuff.
The portfolios with plastic sleeve pages is nice to have as well, or instead of, but if its an outside sale, the wind can be hell on the page turning.
Sarcastic answer - full sleeve tats of all your prints.
i use a mix of portfolios and cardboard backed prints in plastic sleeves. i get the cardboard from work and cut it down to size. if it's not too windy out, i'll run wire from the tent legs and bulldog clip prints to that.