For me, staying at the same agency has helped. People all know me there and are familiar with my skills and good work habits. I think it is harder when you jump around a lot or go into a new agency and have to prove yourself all over again. I meet people at my agency every day that I don't know but seem to have heard of me. Most of them lately empathize with what I have to do
In all seriousness though, with the way the economy is today, tied in with how many fields are flooded with qualified employees, I think it is wise to try to go this route.