Romana = Mary Elizabeth Winstead
http://i178.photobucket.com/albums/w275/kids4you/Girls/MaryElizabethWinstead.jpg

Wallace = Kieron Culkin
http://www.ba-reps.com/artists/126/2238/joe%20-%20kieran-.jpg

Lucas Lee (the skate boarding exboyfriend) is the guy who played the Human Torch in the Fantastic Four movies

http://www.hollywoodreporter.com/hr/content_display/news/e3i30fd5ce301fd7727c77c6830dcdbc3d6

some of the others
http://farm4.static.flickr.com/3353/3212106579_2e1289036d.jpg
http://farm4.static.flickr.com/3470/3212951758_4f86064352.jpg