[Xastir] georeferencing maps on osx?

[Derrick J Brashear]

Actually, I'm looking for pointers to elsewhere I might ask this question.

I have scanned USGS quads I want to georeference myself, for use with 
xastir. I'm not even sure what I'm in for, I assume selecting 4 points by 
mouse, keying in coordinates, and possibly rotating, resizing or 
resampling to get something sane. Am I screwed short of spending big money 
on an expensive package to do it?