Yes, those satellite beacons are AWESOME. They use those in the Gulf of Mexico helicopter flights to/from oil rigs. In these parts, there's no need to hit the emergency button, though. They have an impact activated switch (more than a few G's shock automatically activates them).
Several have gone off on "rough" landings... usually no major injuries, but the choppers get banged up pretty bad on those.
When I was taking flying lessons, my inspector told me a good landing is any landing you can walk away from... a GREAT landing is any landing where you can use the plane again.