another GPS idea - speed-sensitive voicemail

[Mark Eichin]

> Anyway, I am thinking there might be many uses for speed-based
> settings--enough to justify a speed-based 'cron' like utility?  Perhaps...

Yeah, you could generalize "run-things-when" to
  time - cron
  ground-speed - this thing
  place - location-based-services

This suggests that altitude might be something to check as well,
though as someone else pointed out that's a little late to enable
flight mode :)