I have been thinking about maintenance (it's a long way off, but a girl can dream, right?
), and I have thought that maybe something like South Beach would be a good guideline to follow for my maintenance plan (i.e., the rest of my life). It reduces carbs, but allows some carbs that are lower on the glycemic index. It also allows fruit and low fat dairy in moderation. Unlike Atkins, it doesn't allow lots of fatty foods--which I like.
One thing I like about IP is that once you are in maintenance, if you backslide, you have the option of going back to strict Phase 1 eating until that extra weight is gone. I have a good friend who did just that recently.