you can make a router table. it's a valuable tool for any shop.
all you need is a small wood table and a router. here are some how to guides
http://www.woodworking.org/WC/GArchive98/7...johnsrtab1.html
http://www.woodshopdemos.com/smr-rob-.htm
you can set it up to do most of the curves on your guitar or do straight edges (doubles as a jointer) and you should be able to use it to do what it is you're talking about.