Britney -- Hustlin' for Snacks!

TMZ caught the travelin' Spears, her untrusty sidekick, Sam, and her little dog, too -- hitting up the porncentric shop on Sunset Blvd. last night. While the weavewreck perused books on the Kama Sutra (looky these positions!), all she bought was a necklace -- and a sandwich.

Brit's dominatrix personality sometimes needs a little vittles, y'all.