The Star Trek corset was made by EveningArwen, and is available at her store on Etsy.com. I can only judge by the, um, cleavage it has created ... but that right there says it's quite a nice corset. She'll make them in any color you choose, so Engineer and Science officers can be equally represented with the sexy. I bet you can get this just in time for a midnight showing of the J.J. Abrams reboot.
The Star Wars corset also hails from Etsy from a maker named oceanrain1985. It's a little more subtle than the Star Trek one, but is a nice change of pace from those Slave Leia bikinis and sexy Imperial Stormroopers. If you're going to try and tempt the Jedi away from celibacy, you have to get creative, you know.
The only thing that could top these? An Iron Man corset, complete with glowing reactor in the chest. Someone get on that.
[Thanks to Jacob for sending me the Trek corset]