Hey, at least you are thinking creatively (like a lawyer); but, I don't believe a second UG would help. I'm in the same boat, I had a lack-luster UG GPA, and I partied and worked too much and didn't care about grades. Well, now I am paying for it. Since graduating in '98 I got my master's and had a 3.61, not bad, but like you said, they care about the UG GPA not the grad.
Here's my advice: Study your arse off for the LSAT, or hopefully you already took it and did well. Then go to a local school for a year and transfer out if you are really concerned about attending a particular school. If you do really well as a 1L, you can go almost anywhere.
Look forward, not backward. Good luck.