I know very little of NFAs/DFAs/FSMs, or even string parsing in general, but a year ago I built a URL matching engine using exactly this method in Python, in combination with Google's RE2 library (https://code.google.com/p/re2/). It was far faster than anything else I experimented with, and RE2 also improved the speed dramatically by eliminating backtracking.

Nice to know that what I made is considered the best solution algorithmically.