Why are libertarians associated with the right?
Dude, it's because they are on the right.
For example, consider this the Political Matrix scores, which can be linked to with the PM button above. 1045 posters have taken the quiz, and here are the average economic scores by party affiliation:
Democratic -4.13
Republican +4.39
Independent -0.65
Libertarian +5.14
Green -5.94
Constitution +4.76
Other -3.87
Decline to State -0.48
Bear in mind that positive scores are further right, and negative scores left. Sure, it's a small (and self-selected) sample, but it should be obvious that at least among the posters in this forum, and by the standards of the Political Matrix test, Libertarians are the rightmost group. Even Constitution party people, who are considered right-wing nuts, are not as far right as Libertarians. This is only one data set, but I encourage to find other data and you'll see a strong correlation of self-identification with the LP with economically conservative benchmarks.
Where do you see the averages, and how different are they for the social side (what I really associate conservatism with)?
Here is what Angus is talking about.