Since I work for people I got to know in the real life, I go under my real name :) But I've also seen one man shops going under some company name. Sometimes it helps to eliminate irrational fear of subcontracting to a single person that might not be capable of doing the whole project, or helps to scale up into a bigger team later without the need to explain why not all job is done by the original freelancer single handedly. I'd prefer real names though. I think, when it comes to getting some work done, people work with people, and trust rather specific people and less - companies or abstract brands.
Yes, it creates trust. If I were the buyer would never deal with someone who used a fake name, a handle or a pseudonym. Trust is your most important currency when it comes to building strong relationships with clients and being able to price competitively.