Thanks for the quick reply to what's doubtless an FAQ! (I did look a little before asking, honest.)
I'll post an update when I play with the info you have offered up; the in-laws in question are 10 minutes away, and I suspect I'll do most of my tinkering when the Blu-ray player arrives.
Practically speaking, how "clever" can one get in 15 keypresses or less? I suppose that will depend in part on how clever the TV is...