In case some of my story helps, here's the gist of it:
I also had a good undergrad gpa, about a 3.84. However, keep in mind that the gpa you graduated with may not be your actual gpa. Any college-level classes taken at any other institutions (i.e., not at your undergrad college) will be factored in, as well as any study abroad work (if it was through a US college).
I went to law school (top 25 I guess) and while I did very well my first two years, after I worked for the summer after my second year I became disillusioned and disappointed and knew this probably wasn't the right career for me. Thus, I really slacked off my third year and graduated with a 3.2. I then went on to do a federal clerkship, and worked at two different law firms in two different areas of law.
I won't go into how and why I decided to switch to medicine (although I could if you'd like - that's what I've been answering in all of my interviews), but when I decided, I had been practicing for about six or seven years. I started volunteering at the local ER, and six months later got involved in clinical research there. I quit my job at the end of the year and started a formal post-bac program so that I'd have a committee letter (which is invaluable as a non-trad in the application process). I got mostly As (a 3.86), and when that was factored in with all of my undergrad classes, ended up with an undergrad gpa of 3.77 (undergrad and postbac are grouped together). I took the MCAT and did ok, a 30S.
I applied early and broadly, and have received nine interview invites (two I declined). I have been accepted to five medical schools so far. Feel free to check out my mdapps (look to the left under my screen name). In my interviews, not one person brought up my 3.2 law school gpa. Then again, it was some time ago. I think that they're much more interested in my post-bac classes and that I proved I can do well in science classes (and have done so recently). I have been grilled in a couple of my interviews (Loyola, Tulane & UVM) about when, why and how dedicated I am to changing careers. They're very interested in my motivation.
The bottom line is that your low law school gpa will be the least of your problems. You will need to get a lot of clinical experience so that you can show you know what you're getting into, and are still passionate about it, and you will need to show that you can do very well in your post-bac classes. Another vital part of your application will be knocking your personal statement out of the park. You're going to have to cover the why and the timing of this switch, and also convey your passion and dedication to medicine. Because that will probably be the hang up in most adcom's minds as they look at your application. In fact, the assistant dean that I interviewed with at Tulane said that last year there'd been a lawyer that she'd been tempted to invite in for an intervew, but that he really hadn't made it clear why he wanted to become a doctor, and that she had the impression that he was applying more out of hating law than loving medicine.
Anyway, I think you can definitely get into medical school. Just be aware that it's a long process. It's been two and a half years since I made my decision to switch, and I'll be starting medical school in a year. I don't think that you need to practice as an attorney in order to get into medical school, but it might be a good idea to practice for a year (if you can stomach it) for two reasons: 1) to be able to say that you practiced and followed through but that your calling is definitely not as a lawyer; 2) you can save up money to pay for your post-bac; and 3) it will give you an extra year of obtaining clinical/research/volunteer medical experience on the side. Then again, if you start volunteering now, I suppose you can cover point 3 during your last year in law school now. If you decide not to practice for a year, but to start a post-bac program this coming summer (which you can easily finish in one summer and two semesters), then you must start volunteering now, and be sure to have a very good answer for your career change. Definitely don't practice law for a year if you absolutely know you will hate it and think it's not worth the benefits I described above. I believe that you would still be able to get into medical school regardless if you have all of your other ducks in a row.
Also, you say that a law degree can be used in conjunction with a medical degree. To be honest, I'm not an expert, but so far the only jobs I can think of that would do so would be as a patent attorney, a consultant, administration, or a job related to health care policy. If you have an interest in health care policy, you should definitely start exploring that now, and I believe it would be a huge plus to your application to medical school. The others career goals, not so much. They don't want to train people who don't want to practice medicine or benefit the field significantly.
Good luck, and feel free to send me a message if you like.
Believe me, baby -- I'll be spinning right there with ya. Tap dancing, begging for mercy, etc, etc, etc. 
