I've found that at my current job I seem to get more respect as time goes on. Part of that reason would be that I admit what I don't know, I treat my coworkers the way I hope to be treated, and I take care of any problems as well as my deliverables in a fast, efficient manner.

One of the other comments - 'A BOFH should be feared, not respected' - is perhaps, true, but unless you're in an extraordinarily IT-centric organization, that kind of attitude is much more likely to hurt rather than help.