President Obama promised his administration would be transparent, and in a move to make good on his word, last month the White House released a list of visitors to the White House since he took office. Although the limited list is far from complete--the White House stressed that it's voluntary and excludes many names for security reasons--there were a number of celebrity visitors in the mix. Here's a look at some of our favorite stars that have popped in to see the Obamas this year.