Multiple Sequence Alignment

Given two pieces of DNA we can use ideas from mathematics to determine a distance between them. This distance gives a biologist information about the similarity or difference of the two pieces of DNA. If finding the distance between two DNA pieces is useful, would it not be even more useful to find the pairwise distance between a group of DNA sequences? This could certainly be done and can indeed be very valuable. However, one might approach the problem in a different way.