Good tips... After a bit of searching, I found
this thread which was pretty close to what I wanted. The blank apps there are still launchable, but they basically launch then quit, taking you back to the Springboard. Minor annoyance.
I looked at doing the SBIsRevealable trick, but this relied on setting the SBEnableAppReveal property, which then also hid YouTube, Safari, and iTunes. I could have disabled the property in those apps, but didn't feel like going to that amount of trouble.
I guess this is close enough until some better way comes along.