i saw these on craigslist and thought i would post in case someone was thinking about building a portable slider. $5 per drum, sounds like a pretty good deal.http://www.craigslist.org/pen/for/144515306.html
hahaha you can get thoes for free at the car wash. Once there empty, they just throw them away to be recycled. The guy in my town was more than happy to give them to me.