You gotta be real careful with "verbal intimidation". Some people will take you for your word, and thats not always a good thing. It can lead to physical altercations, or as others have said, the ruining of your reputation.
But if you want to IMPOSE RESPECT, which is what you seem to be asking, you need not look farther than posture. The way you hold yourself is the gateway to acceptance, as well as armageddon. Simply holding your chest out, shoulders back, chin up and walking with conviction/confidence can usually keep MOST "bullies" at bay. See most bullies like to get a reaction out of you like others have stated before. Others, are just trying to stir the pot, to be a catalyst of cataclysmic proportions. They just want to set the world on fire(like the joker in the dark knight).
If you're dealing with the latter, your best bet is to keep your nose out of it. Ignore them, hold your pain inside and allow no one to realize behind your real eyes you cry tears of sorrow. They need not know your emotional side, only the one who shows no fear in the face of destruction. You can go the crazy route but understand you will be labled as the crazy one. Id rather go the silent but deadly route, if they dont know your intentions, they dont know what you're willing to do...