I did some searching on the Wayback Machine and was able to recover the dead link: Auto rotate with a vector. After downloading and trying Version 3 of the script, I see what you mean about this being a very handy utility. It sure beats rotating the image manually to get rid of the skew.
Thanks for tracking that down, I'm using it already!
Or you could simply use the measure and rotate tools.
Rotate works pretty well with the "corrective" version, where you can align the grid to the image. But I like being able to pick two specific points that I want to align. Sometimes the grid doesn't match up with what I'm trying to guide by.