I cludged up a cart from an old gas grill frame. Added in side burner, stainless side table, light, churchkey, tool hooks. Had a lid hook and speakers but took them off (lid hook never worked right, speakers got replaced by bluetooth).
Total cost less than $5 (and most of that was the speakers I'm not using anymore and re-donated).
Build thread here.
http://tvwbb.com/showthread.php?26480-Behold!-The-smoker-cart-of-awesomness!!!!!
I changed the base to a solid metal one, but other than that, its still chugging along 4 years later. I didn't use it for a while but brought it back out I think last summer. It is the easiest way to light the charcoal I have and the side table comes in handy (though I sort of wish it folded down to save a little space. The real trick is finding the right old gasser frame. This was a made in the USA Charbroil from probably the 80's that my neighbor was getting rid off. A lot of the new ones would be total junk, but you never know what people might throw away with grill season, memorial day, Father's day, 4th of July, etc... coming up.