Leopard: disable “Open with” previous versions of applications in Time Machine?

So Leopard does this really clever thing where, if you don’t exclude it from making backups of your Applications directory, it will let you do a right click / “open with” and select previous versions of apps Time Machine has backed up. The rub: you can’t turn it off, and if your Time Machine drive is connected but not spun up, it’ll wait until the drive gets going before populating that list and giving you the menu. Anyone discovered how to disable it (short of excluding the Applications directory from backup)?

Also, big ups to Conrad for sharing Stamatiou’s really useful OS X hack for turning off safe-sleep mode.