I absolutely want a landscape lock
I'd be perfectly happy to have it work with the current software unchanged. The iPhone might put up a dialog to alert the user that "This setting will only be used with apps that support landscape mode"
With such a setting, the phone will lock in landscape wherever possible and essentially be locked in portrait wherever landscape is not supported. This would completely eliminate unwanted flipping from ALL apps when using the phone in bed.
(Safari allows you to workaround this by holding the bottom of the phone at the top, but many apps don't use that trick, and many people don't know the safari workaround)
I really want landscape lock