Thousands of fans infiltrated San Diego this week for Comic-Con, the annual gathering of all things related to the sparling comic boom industry, bringing out everyone from Hollywood A-listers to zealous fans.

Several actors and actresses were out in full force.

Two of the most famous geeks  girls to attend , Olivia Munn and Felicia Day, both tweeted about the costumes.

Puttin on my Sailor Moon, Olivia Munn tweeted tweeted. I ♥ Comic-Con. So much. Sailor Moon refers to a Japanese cartoon franchise that invaded the U.S. in the early '90's.

Conan O'Brien made a joke about the smell at Comic-Con. I have arrived @Comic_Con. The air is thick with the smell of Cheetos and celibacy, he wrote.

See the photos below: