(Copy of part of the personal e-mail response.)

Comm devices listed by my perceived use in dire circumstances:

VHF Radio (+ backup)
SatPhone
Cell Phone
Epirb
A/C mounted ELT

Add: Smoke and mirrors.

Another possibly usable technology is the personal band radio with
GPS. It's small enough to carry on the parachute strap or in a pouch
or pocket. But it's only good for fine tuning the rescue when within 5
miles or so, and if the response team has the same radios!
I have changed to a square parachute to help in both the choice of
landing areas and dealing with landing in up to about 20 MPH of wind.
You should not fly with a square chute unless trained.
In Australia the FLARM has been used by tow pilots to find their
retrieve. If still functioning after a crash it is very useful to the
response team who can also carry one.
Jim