In rec.aviation.piloting, on Thu 30 Aug 2007 07:06:41p, "Gattman"
wrote:

Ohhh, man... I guess owe my CFI an apology. I always thought that
was what I was -supposed- to do. On the flipside, I've never had a
problem preflighting and hanging out while she finished up a previous
lesson, so hopefully she doesn't completely hate me.

Well, considering the fact that the previous lesson is unlikely to get back
until the start time for your lesson, there's not much else you can do.
The flight schools that I have dealt with over the years have always billed
by aircraft time (Hobbs or tach). Very seldom have I ever been able to
squeeze a 1 hour flight out of a 1 hour booking slot.