Here is a cool thread Pete started.
cool thread (http://www.hobbytalk.com/bbs1/showthread.php?p=2209857#post2209857)

And the URL for the site;
link to HO Buildings (http://www.hobbylinc.com/prods/ug.htm)

look under ebay seller acol. he has all kinds of things; billboards, bathrooms. first aid buildings, entrance gates, beer & food booths, judges stands. etc