I just got back from Oregon and picked up a pair of the brand new Nike Free 3.0, and I gotta say I love them already. I previously owned a pair of the Nike Free 5.0, which have a bigger heel and still enjoy wearing them. However, I definitely like the lower profile of the 3.0 and I feel like your feet are a lot more secure and tight in the 3.0. I went with the Black ones (the product number is 553684-001), but Nike offers 5 other colors, with a few of them shown below.
Overall I would recommend this pair of shoes for just training at the gym, going on runs, or hikes, they have good heel support and are very comfortable.
Here is the the direct link at the Nike Store: Nike Free 3.0 Black