Taking the worst-cases in your list of scenarios ? remote area, so possibly no cellphone coverage; or not everyone in group has a cellphone; or location-specific instructions difficult due to unfamiliarity with the area ? you might consider supplying everyone with a decently-powered GMRS 2-way radio when you're on an outing.

Not the least of their advantages is that they're inexpensive to buy, so everybody can have one; cost you nothing (in monthly service fees) when not in use; not much larger than your typical cellphone.

Another plus is that being so equipped allows flexibility in case your predetermined meeting place becomes no longer viable for whatever reason. And for kids, the ability to instantly communicate with you in an emergency is reassuring (for you and them).

Of course, have to remember to recharge the rechargeable type, and/or make sure those w/replaceable batteries have juice left in them.

And I know what you mean about your wife's quick-to-find-you ability, a skill the military envies. I think they learn that in wife-school, though my wife (correctly) insists she only needs to head for the sporting goods/fishing/hunting/gun/camping department <img src="/images/graemlins/smirk.gif" alt="" />