I'm not actually a huge fan of talking about the two body issue - the question of finding two jobs for both members of a couple, that is, not the college physics orbital dynamics problem. Unlike the physical problem, there is no one-size-fits-all analytical solution to the two body issue in employment.
The two body problem often refers only to dual academic couples. Certainly, a good many scientists are married to fellow academics. In some ways, this problem is the most straighforward to solve, since it involves a single employer: the university. But universities can be large or small, public or private, urban or rural, all factors that can impact their ability to accommodate a dual academic couple.
Because two body issues are so diverse and different, perhaps it is worth talking about them in terms of specific anecdotes and individual solutions rather than trying to define prescriptive remedies. So here I'll talk about my own search for a solution to the two body problem. The decisions we've come to have been a result of much talk and discussion and negotiation and soul-searching. So I am not looking for further suggestions or advice, but simply want to lay out our scenario and the various factors that have played into it.
My new job will be in a small department in a small college town in a sparsely populated state. My husband is not an academic. The nature of his field is that when he posted his resume on Monster.com, he immediately got swamped with phone calls from the greater metro area of where we currently live, but not a one from where we plan to move to. When he did get a phone interview at a company an hour from my new job, they wanted him to start the next day. As it stands, we are moving in less than two months, but he still has yet to find a job. However, the time scale between applying for a job, getting an offer, and starting the new job is a lot shorter than the academic cycle, so we aren't too worried.
It does, however, leave us with some amount of uncertainty as to where to live. Telecommuting is not really on the table. The best concentration of jobs appears to be about two hours away from the university, so we are splitting the difference by buying a house in a city an hour away from the university. Fortunately, the city has other features to recommend it to us. However, it will likely mean that both of us will have hour long commutes.
This whole exercise of negotiating where we buy a house (down to which side of the city we'll live!) has given me a lot of insight into why the two body problem can be such an issue when departments are trying to hire women. If my husband had been an academic, the university might have been able to find a position for him. Since he is not, however, there was not much they could do to help. There simply aren't companies in this small college town where my husband would fit. In an urban area, this would be much less of a problem. I had thought that my husband's job was pretty portable, but it turned out to be less portable than I thought. If my husband and I had not be able to compromise, if his job were less portable, then it might really have come down to a choice of career or family. And who knows, another woman might have left the pipeline.