In answer to your questions: Yes, I do have more than one piercing. I currently have my lip, anti-eyebrow, and vertical and horizontal nipple piercings. I used to have a five barbell star between my shoulder blades as well as my tongue. You might well guess that I'm very intrigued by body modifications. However, I find offense in calling ears, belly, tongue piercings trendy mods that don't count. Here you post complaining about workplaces basically stereotyping pierced individuals as unprofessional, but yet you stereotype people who've got those piercings as trendy sheep, eh?
It seems as though you need to stop being hypocritical before you start pointing fingers.
Anyhow, I think businesses are totally justified in not hiring someone based on piercings. They are businesses catering to their customers. So of course, if you are a fine, fancy restaurant whose customers frown upon piercings further than ear lobes...you are not going to hire someone with a lip ring waggling around her mouth. Just like, if you were to walk into Hot Topic wearing a business suit and carrying an attache case and request an application, it's not likely you'd be taken seriously.
Work is work. It's not mandated to be the fun place where you get to express yourself creatively in your appearance. And if you want that ability in your workplace, it's your responsibility to find a job that offers that freedom. I agree that it's frustrating, but if you're that creative, you'll find a way around the problem (and I don't mean by just donning a clear retainer in the piercing while you're at work). Plus, I think it's more fun to challenge people's preconceptions. They see you in full out business attire at the office and marvel at your work ethic and intelligence...so forth and so on. And then they're just blown away when you tell them who you are or what you do or how you dress outside of work.