It's Friday, Friday and we used up all our Rebecca Black jokes already. Today (Aug. 16) in the celebrity Twitter-sphere, stars threw shade at one another, made us laugh at their witticisms and quoted 'Mean Girls.' All in all, not a bad start to the weekend.

Lindsay Lohan wants to help make fetch happen.

We see what you did there, Josh Groban, and we love it.

Adam Lambert teases that a new song is on the horizon.

That time Justin Bieber basically compared himself to Michael Jackson.

Rihanna spent the day taking pictures of her underwear because she's Rihanna.

Seth Meyers has something to say about 'Blurred Lines.'

We've all been there, Pete Wentz.

Hoping Ice T directly quoted himself here.

Rainn Wilson has simple requests from his fans.

Joss Whedon has grand visions for the future of humanity. Mostly flying cars.

Bless your heart, John Cleese.

Kevin Jonas had to have meant that dreams hate alarms. Right?

And Kim Kardashian throws some shade Katie Couric's way.

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