The Week in Celeb Twitpics (PHOTOS)

Rihanna's Instagram!
See her sexy and fun photos!
Beyonce's Tumblr Pics!
Beyonce shares photos from her Tumblr.
Summer has officially kicked off and your favorite celebs are taking full advantage of some fun in the sun.

Tyra Banks, Lady Gaga, and Rihanna all stripped down to nearly nothing due to the rising temperature.

Meanwhile, Hayden Panettiere tries out a new ‘do for the summer by rocking new all the colors of the rainbow in her hair.

Who was caught heating up Brazil with her new DJ set? Which two famous sisters tweeted some summer sibling love?

Click through the gallery above to see this week’s celebrity Twitpics.