According to National Geographic, the leading causes of nerd boners are:
1. Natalie Portman
2. Pictures from Upcoming Comic Book Movies
3. Stiff Breezes
There, I helped you with the second one. For numbers one and three, I recommend google image search and standing outside. But be careful: experiencing all three at once could create an unhealthy drop in blood pressure.

Natalie PortmanAlyson HanniganFIXED.
1.
Natalie PortmanAlyson HanniganLiv Tyler as ArwenNOW its fixed.
1.
Natalie PortmanAlyson HanniganLiv Tyler as Arwencartoon characters in dressesNOW it's double fixed.
Natalie PortmanAlyson HanniganLiv Tyler as Arwencartoon characters in dressescomputer game characters with big tits/weaponsNOW it's treble fixed. This could run and run.
Natalie PortmanAlyson HanniganLiv Tyler as Arwencartoon characters in dressescomputer game characters with big tits/weaponsPrincess Leia's metal bikini, for the win!!!
Not so fast IED:
Natalie PortmanAlyson HanniganLiv Tyler as Arwencartoon characters in dressescomputer game characters with big tits/weaponsPrincess Leia's metal bikiniHayden LePetomaine in a stormtrooper helmet.
http://64.111.216.18/photo.phtml?post_key=2497&photo_key=3315.
I'll see your Hayden in a stormtrooper helmet and raise you two femtroopers:
http://tinyurl.com/ynqch7
Not bad. They look like a couple of shaved wookies with tits, but not bad.
Mmmmmm. Wookie tits.
Improvised Erectile Device 09:15 – "Princess Leia Bust" is an ad on the right of this screen right now. Well done!
FnB: You should see what happens when I start talking aabout getting fine blowjobs from that redhead from the Busted Tees ads.
Natalie PortmanAlyson HanniganLiv Tyler as Arwencartoon characters in dressescomputer game characters with big tits/weaponsPrincess Leia’s metal bikiniHayden LePetomaine in a stormtrooper helmetBugs Bunny dressed as a girl bunny.I know I’m not the only one.