Bang commands are such a wonderful feature on DDG. Not just for searching other engines when the DDG results aren't what I'm looking for but also for ecommerce sites. The frontpage of most sites are extremely heavyweight and you have to go through a ton of garbage just to get to a search box. Being able to add !homedepot to a DDG search and have it send me to the search results page at Home Depot and not the DDG spidering of the site is pretty nifty feature. I do most of my searches of shopping sites that way now.