I suppose there are issues around what view of the law we take, which determine what part we think the OT Law should take in the Christian life, and then there are the broader issues of legalism and Christian living.
Phillips raises the question well (by providing some thorough observations of what people say around this area), and it'll be interesting to see what answers come in the comments.
Dominic Smart's article at BeginningWithMoses.org is worth a look on this topic:
"Legalism isn’t a matter of having rules, structures, limits or instructions in our congregations or individual lives. While they can be overdone, and often are by people of a certain temperament, they are necessary for godly order in any fellowship: God has given many to us in the Scriptures. The opposite of legalism isn’t lawlessness (antinomianism, as some like to call it), which is nothing more than anarchic pride. Nobody is delivered into that. Christian freedom isn’t freedom to do whatever you want: down here none of us is safe to be let loose with such a freedom; up there - well, we’ll be different then! Legalism is primarily a God-ward thing. It’s a way of making and keeping yourself acceptable to God."ps: Tom, on our previous conversation about what is a human being? - how about kicking off the discussion in the same sort of way Phillips does here.