I'm a current Peace Corps volunteer, and I'll be entering law school this fall as a 1L. In my entering class of PCVs, there were a number of lawyers. They all made great volunteers, and by the end of the first year, they'd all terminated early. A lot of this has to do with the sort of work the Peace Corps does. Most of the work we're involved in is done at the most basic level - showing people how to fill out forms, where to look for grants or aid, giving basic health seminars. Our responsibilities are relatively undefined regardless of what program you're in (with the exception of teachers, who have a required curriculum and number of hours per week) and productivity is extremely
low, resulting more from the environments we work in than the actual efforts of volunteers. This proved incredibly frustrating to the lawyers coming in to the Peace Corps, who were used to daily intellectual challenges and stimulation that you simply won't find in the Peace Corps, despite the other many values of the program. The Peace Corps does provide challenge and stimulation, but of a different sort. You won't be flexing your brain muscles trying to figure out a problem, but rather trying to overcome bureaucratic hurdles to simple and necessary projects, dealing with massive amounts of downtime, and trying to develop relationships that will help you get something/anything accomplished. Which is why the lawyer survival rate in my group (and, in fact, all groups in my country at the moment) is zero.
So think hard about it; while PC service is rewarding and has its benefits, you can travel and donate your time/efforts to those in need in ways which will allow you to more squarely apply the skills and mindset gained in law school/the practice of law.
check out http://www.abanet.org/ceeli/
, or google some other international NGOs, many of them have use for lawyers or those with a legal background.