For those thinking about buying a SPOT, you should know that you can setup multiple "profiles" within SPOT. (FYI - I have no affiliation with SPOT, other than as a user)
Each profile contains info about who to EMAIL or SMS for the Check-In/OK and Help buttons, and what message to send; plus your Primary and Secondary Emergency Contact Info and an Additional Information (free form text field - several hundred characters only I think).
I believe that you can send the Check-In/OK and Help messages to up to 10 contacts (I think).
Only one profile can be active at any one point in time.
So you could setup a separate profile for scout trips, canoe trips, hiking, or 4WDing trips - whatever makes sense. You can edit these online as you wish.
For example you could setup a scout profile to send the OK message to your Regional Leader, partner and several parents but the Help message may only go to the Regional Leader and your partner.
This profile system is useful if you want to loan your unit to other people, you can set up a DougR profile, a Sue profile etc ... (I'm not sure how many profiles you can create). Useful if you want to share the unit.