The Nature Jobs Prospects in v. 45, 17 Jan 2008 (p. 369) seems to emphasize relocation as a key contribution to a successful post doctoral experience. As a scientist who decided to remain at the same institution where I got my PhD, in order to accommodate family and work goals, I respectfully disagree.
At the end of my PhD on ethylene signal transduction, it was clear to me that I wanted to keep studying the receptor's biochemical properties. However, leaving town would certainly jeopardize my personal life. As my PhD advisor put it 'You're stuck here'. Of course I disagreed with him at the time. I even asked him who, in the world, I should go work with that was doing what I wanted to do. He came up with someone in Japan, maybe. What I told him was that I needed the tools to do what I wanted, and there should be competent people at this institution from whom I could learn. I wasn't bluffing...
Instead of seeking a postdoc in plant biology, I instead focused on what I needed to learn to be successful in that field when I got back into it. My first objective was to further my knowledge in enzymology. I was able to find a postdoc in the Dept. of Chemistry that worked on mechanistic enzymology of oxalate decarboxylases. My second postdoc has been dedicated towards learning membrane biology techniques. I'm studying glucose transporters in a mammalian cell culture system.
I have been in three different departments, in three different colleges. I was a graduate student in a lab with five postdocs, where each question was greeted with five different answers. I was the only postdoc in a lab with eight students, each wanting 2-3 answers to a single question. ('What if it doesn't work?') I have experienced conditions of high and low funding. I have gained insight into lab management and university politics beyond my expectations. I had two sons, one at each postdoc, and was exposed to issues that affect most women in science. (Pregnancy, maternity leave - how many experiments can I realistically plan for the next 12 weeks?)
I wonder sometimes whether I would have learned more if I had moved to a different institution. My advice to graduate students is always to focus on what you want to learn, not where you want to go. I have been able to broaden my horizons without leaving town. Will it help me get a real job? I hope so!