Starting in version CS3, you can make InCopy Packages that are expressly designed for remote editors. Much neater than trying to find the files yourself and zipping them up and making sure no one edits them while the outside editor has the stories. When the editor returns it (as an InDesign Package), the layout automatically updates w/their changes and checks in their stories.
Another solution is Dropbox (http://dropbox.com), a free program that adds a "My Dropbox" folder to your local hard drive. If you put your ID projects in there, and your editors also installed Dropbox, then the folder acts just like a server. It's really cool. I demo'd it working with ID and IC at the Print & ePublishing Conference last month. And I have three or four publishers using this solution after some training from me, even for in-house use (when local server connection is spotty or slow).
AM