Great thread!
Recently I was browsing YouTube tutorials and someone had posted chat roulette videos. They used it to practice, then posted the videos. I think this is a good precursor to performing in person, like the subway or park. Let you get over the shakes before taking to the streets. Hell, if you screw up just end the chat.
I tried performing on Chatroulette once. The typical webcam and Internet connection make it a bit difficult, especially during high-traffic times during the day. And at night it's all gross guys stroking their junk...ewwww....
Practice your routine - not just your moves, but your patter. Do it a LOT. Until you're practically sick of it. I don't advise practicing in front of a mirror too much, since you're seeing a mirror image and not the real deal and can miss something in the angles that a spectator might see. Performing in front of a camera is cool, though - and do so from different angles as well, so you can see anything that might be giving your trick away, so you can either fix it or be aware that for this trick, this angle is weak, etc. Don't look at the video while performing - review it after you've done a set.
For me, I have a set that I've been performing now - it's got to be approaching a thousand times, literally. I do it, with some variation, at the hospital where I volunteer one day a week. I perform for kids in the pediatric unit and pediatric ER - and there are other options as well, such as chemotherapy patients and such; people who need a distraction from the pain. Perform in small sets like that, and you'll get the knack for it quickly enough - just be sure your skills are up to the task before applying. Another alternative might be to perform somewhere like a local library - in most cases you'll get a small crowd, not enough to overwhelm but enough to give you the practice you need.
BTW, remember one thing above all - you're human. You'll make mistakes, you'll screw up tricks, whatever. But more importantly, it doesn't even matter in the grand scheme of things. It's why people practice magic (and it's why people practice martial arts, too). But even when you screw up, if you have your personal charm turned up to 11, your audience will be happy for the experience anyway. Charisma can take you a long way, and being a magician requires that you get your charisma out, dust it off and show it to the world. You can be the perfect trick robot, getting every move down cold but with zero charm and little to no patter, and your audience will yawn. Bust out a smile, a sense of humor and colorful patter with room for improvisation, and even if you screw up a trick, your audience will be entertained and have a happy experience.
I ran into a room full of teenagers at the hospital yesterday - it was possibly the largest audience I entertained for there. There were perhaps seven or eight of them, patient included, both genders, all family members of the patient. Normally I do a brief three-trick set and move on, but this time, I had time to spare, the unit was nearly devoid of patients old enough to appreciate a little magic performance. I had them going, frying brains left and right like a cannibal short order cook at breakfast. I ended up doing five tricks, plus I taught them a simple automatic trick they can use to entertain their friends. That might well have been the most fun I had in a performance. The kids were less than half my age, but I was still able to get them going, have some laughs, slip in a few jokes that they didn't find lame. I think one of my best was when I was introducing a trick with the line, "Do you believe in psychic powers?" One of the spectators starting talking about how they have such powers and practically know each other's thoughts, to which I replied, "...and they call it 'Facebook!'" Big laughs all around.
Go out there, meet people and by all means, have some fun! That will be your biggest motivator - it's fun. That fun, once you've experienced it, will motivate you and strip away any performance anxiety you might have had.
