Britney Spears is currently hair-extension deep into her Circus Tour.

The singer has performed in Australia, Dallas and Vancouver, among other locales. In between, she's possibly had sex with Chase Benz and Kevin Federline.

It's a lot for a manic depressive to keep track of. Therefore, Britney can be forgiven for forgetting where the heck she is at times, such as last night in San Jose.

Following her opening set, Spears greeted fans in attendance with: What’s up Sacramento?!? Fortunately, they were too excited to notice...

What's Up, Sacramento?!?

The truth is, this sort of thing happens often to artists on tour or politicians on the campaign trail. Barack Obama referenced the wrong city during a speech a few months ago.

But he didn't tell those around him to "Rock out with your cocks out... motherf%*kers!"

Nor did he complain backstage, into a live mic, that his "pu%$y was hanging out!" during a dance routine.

Ding dang, Brit, those microphone thingies can be complicated pieces of technology, can't they?