Dumpster vs. dumpster

J-Dogg has been wondering why I capitalize the word "Dumpster".

It was capitalized throughout the Seattle Post-Intelligencer article on scavengers that I linked to the other day, and I figured that indicated it was a trademarked term, like "Kleenex" or "Xerox". An entry on Wikipedia confirmed this is in fact the case:

The word dumpster came from the Dempster-Dumpster system of mechanically loading the contents of standardised containers onto garbage trucks, which was patented by the Dempster Brothers Incorporated in the 1930s. The containers were called Dumpsters, a portmanteau of the company's name with the word dump. However it took the Dempster Dumpmaster, the first successful front loading garbage truck (and which used this system), to popularize the word. The word is a trademark of the Krug International Corporation, but today it is often used as a generic word.