Office romance warnings aside, the key here is to play it cool. If you're rejected on the spot you'll be forced to take the stairs indefinitely for fear of running into her in the elevator. Look for the telltale signals—someone that's available and looking will make eye contact and smile. Are you getting that from her? If so, then say hello and initiate a conversation. Keep it light, and keep it brief. If there appears to be chemistry, then the next time you see her, after the idle pleasantries, mention your favorite place for lunch nearby. "Have you tried it? Would you like to?" Bide your time, be direct and good luck, killer.

The number of American workers that have dated a coworker, according to a 2008 Vault.com survey.