Another great gift for V-Day, these HTTPanties from Think Geek are perfect if either you or your lady is a nerd. You're reading Gizmodo, so we're sure about at least one half of that equation.
These panties have cute HTTP status messages on them, sporting "411 Length Required", "413 REquested Entity Too Large", "403 Forbidden", and "200 OK". As long as your lover's wearing the right set, you can always gauge her interest by just peeking in her pants. You know, cause verbal communication is so 2006.