Then I found the PERFECT plug-in to work around the problem. The "Page Links To" plugin by Mark Jaquith is a dead simple method: It lets you create regular (blank) WP blog pages, and then link them to wherever you want. Then WP thinks they're all just regular blog pages, and adds them to your nav menu with whatever title you give them.
You can still style the menu with CSS.
Check out the results on my blog: http://bendingtreearts.com/blog