Amazon.com (and various other online retailers) is selling Ghostbusters boxers. They range from $10-$15US.
I kid you not.
If anyone finds them in a meat-space store, please let me know. Thanks to Chogrin, who apparently scours Amazon for under garments (I’m just joshin’), for letting me know.
[UPDATE]
They also sell these boxes at Gordmans, I have like 5 pairs:) – Kris