Looks like a 10 gallon Corny..
http://www.google.com/search?q=10+gallon+corny+keg&hl=en&client=safari&tbo=d&source=lnms&tbm=isch&sa=X&ei=0wghUcioLojg2gW2v4CwCg&ved=0CAkQ_AUoAQ&biw=768&bih=928
As for use, well brew slightly larger batches and ferment with it, sell it, or just use it as a keg..