It's free Slurpee Day at 7-Eleven

Notice the date? It's July 11, or 7-11, and 7-Eleven, the nation's most prolific convenience-store chain, is giving away free 7.11-ounce size Slurpees all day until midnight at participating stores throughout Colorado.

To mark its 84th birthday, the chain, which has 8,600 locations in North America, and 41,500 stores worldwide, has been giving away free Slurpees since 2002; two year ago, 7-Eleven stores handed out three million of the lightly carbonated frozen slushies.

Coca-Cola -- 7-Eleven's most popular flavor -- is the convenience store's "Slurpee-weight Champion of the Universe," but half the fun is seeing the crazy flavors the chain comes up with for promotional tie-ins. Right now, it's Alienade to coincide with the release of Cowboys and Aliens. The description? "This unearthly flavor combination combines strawberry, raspberry and lemonade in an exciting new way. It's as close as you can get to making contact without risking an abduction."

No purchase is necessary, but patience will likely be a virtue.