Is it Britney?

3/14/2007 11:31 PM PDT BY TMZ STAFF
Photos purporting to be of Britney Spears hopping into a gas station (one of her favorite pastimes) are floating on the net -- only we can't tell if it's really her!

While the pop rehab mom has been snapped in various fast food locations and making pit stops at refueling stations ... this one has even our crack staff stumped!

What do you think??