I use a suite of scripts called Ninja Dojo, which isn't free, but has a script for straightening UVs (which is what I meant to say in the first place). I believe nightshade UV editor also has a function like this, and it is free.
The UV creation for NURBS operations pretty much does what you see there, ie: normalizing the UVs into 0-1. I do basically what St. Sabbath is talking about, unwrap vertical, then horizontal, make the left and right edge straight, then use a script to align all the corresponding uvs. It sucks that it doesn't set things up…