We tried the 3-day with DD awhile back, and it freaked her out. We did some other things, and then took a complete break and went back to diapers. We started the 3-day in a modified fashion, and we're on day 4 and seeing signs of progress!!
Day One: 8 accidents, no potty
Day Two: 6 accidents, 1 potty
Day Three: 4 accidents, 4 potty
Day Four: 4 accidents, 5 potty
So for those of you who struggle w/ the 3 day, try to take what you can from it and modify it as necessary. DD really freaked about the accidents--rushing her to the potty really made her feel like she did something wrong, even though I told her otherwise. She needs a little more relaxed approach--when she has an accident, it's no big deal, she needs to be reminded to go, we occasionally read a book if she struggles to relax and get it out, etc. And today she finally told me she had to go. I'm really pleased with how much better she's doing this time, but I think w/ these slight changes she feels a little less pressure. I think we're going to take more like 7-10 days, but that's okay!
Also, she LOVES this book: http://www.amazon.com/Princess-Potty-Samantha-Berger/dp/0545172969/ref=sr_1_2?ie=UTF8&qid=1295649924&sr=8-2