I'm going to add my own story to the mix...
I got a 2.8 GPA undergrad. I had a rough freshman year (I failed a high level calculus class 2nd semester) as I never learned a good work ethic. I was temporarily suspended from school (a good state school), but then came back and got on dean's list my first semester back. Unfortunately, I got lazy by the end and got just under a 3.0 my last semester in college.
My effort at work is completely different from that of my undergraduate career. I've worked for 4 years in Corp Finance at a media company and have been given an incredible amount of responsibility. Also, luckily, I scored a 750 on my GMAT (even though it took 3 times of taking it). I ended up applying to HBS (not sure why), Tuck, Darden, Fuqua, and McCombs. I was accepted at McCombs (with a bunch of money) and was waitlisted at Tuck, Darden, and Fuqua. I was recently accepted off the waitlist at Darden where I'll be matriculating.
I can offer the following advice for people with a low GPA. First, don't assume that it counts you out. I know I was waitlisted at the above schools due to my GPA (Tuck told me this), but if there's something else you can offer the school, they'll be willing to admit you. For me, I think it was my work experience, as it was very unique and my recommendations were very strong. Also, I genuinely enjoy interviewing, so I think that helped.
Also, try to find any sort of connections you have and ask for advice and ask if they can write a letter of support, it never hurts. If you're on the waitlist, don't be annoying, but try to keep a constant dialogue with the schools and give them a reason to admit you. Make it seem that it's their loss if they don't admit you. Lastly, don't give up. Getting in to school was really really hard (especially due to my GPA), but it's all worth it as I really loved Darden when I visited.
That's my story. Feel free to PM me if you have any other questions.
Matt