First, we must mention Elisabeth Shue. Karate Kid, Adventures in Babysitting, Cocktail, Back to the Future II & III, and Leaving Las Vegas are pretty good nerd-cred titles, certainly in the "important pop culture moments" category. She was a Burger King girl and is a Harvard graduate. In Piranha 3-D Shue plays Sheriff Julie Forester, and is pretty tough.
Dina Meyer has, possibly, the best nerd-cred of the group. Look at these credits: Johnny Mnemonic, Dragonheart, Starship Troopers, Star Trek: Nemesis, portraying Barbara Gordon, Birds of PreySaw I - IV, and an episode of Burn Notice. In Piranha 3-D she plays Paula, who for the life of me I cannot place, but I am gathering she was one of the ill-fated science divers looking into the seismic activity that released the mutant fish.
Kelly Brook plays Dina, a nude model. In real life, she is a British pinup model, known widely for pictures in The Star, Maxim, and FHM. She has appeared in several films and television shows, includingthe role of Victoria Hardwick on Smallville, The Italian Job, Romy and Michelle: In the Beginning, and Deuce Bigelow: European Gigolo. She was once engaged to nerd friendly beau Billy Zane. She also appeared in the September 2002 issue of Playboy.
Riley Steele plays Crystal, another nude model. Piranha 3-D appears to be her first "straight" film, as her previous credits all appear to be porn. She was nominated for the potentially dubious (depending on your point-of-view) Adult Video News (AVN) awards "Best Group Sex Scene" and "Best Threeway Sex Scene" - personally, I don't think the AVNs are any more silly than the Academy Awards, so kudos, Ms. Steele.
Rounding out the list is another porn star, Gianna Michaels. Gianna plays "parasailing girl" who flies on a parasail topless, and gets eaten by piranha. Obviously on both points. Gianna has been a busy girl. She started as a nude model, but soon moved to hardcore films, apparently appearing in over 200 titles since 2004. She also does a lot of work on websites, and the internet is littered with her. As long as we are talking AVN Awards, Ms. Michaels was nominated for 2007 "Best Oral Sex Scene," 2009 "Female Performer of the Year," "Best Tease Performance," "Best Oral Sex Scene," and "Best Couples Sex Scene," and the 2010 "Best Anal Sex Scene." AVN wins include 2007 "Best Group Sex Scene," and 2008 "Best Sex Scene in a Foreign-Shot Production."