This is a problem that I've been struggling with as well.

I started calling myself a consultant, but I've found that seems to be a title that a LOT of hacks around here use.

I think the best approach is to make a name for yourself. Do people say "Seth Godin, the marketer" or just "Seth Godin"? When you can say "I'm notduncansmith", you can charge a premium, because no one else can say "I am notduncansmith" (Uggh, did you chose your username for the sole purpose of ruining my example??).

Long story short, when you get a reputation, title doesn't matter as much, and you can just be you.