One thing I'd like to throw in is the benefit of using phones which have a GPS built in.

I recently purchased a new Blackberry Pearl 8130 which has a GPS built in. I live downtown and have had mixed results with getting a lock amongst all the buildings with some GPSs. Yesterday I fired up google maps (the mobile application for phones and PDAs) and it gave me the option to find my location without the GPS signal using tower information. It pin pointed me to within 300m.

Granted this requires the phone to be able to talk to a tower but if for any reason the GPS won't work (heavily wooded area? Weather? etc?) and you're within range of a tower (there are quite a few areas in Jasper which are like this), it's just another tool in the box which can help you find yourself. The other benefit with google maps is that if there is a road, cut line, etc. nearby it is likely to show in the satelite images.

A lot of phones have a fake GPS though (called aGPS which IMHO is a very bad name) so their location doesn't work without cell service.

If you depend on your cell phone as a survival tool, there are only two rules -

1. Verify you are going to an area that has cell service.
2. Verify you are equipped to keep it running.

Study the results of those that didn't - i.e.

- James Kim & family
- Mt. Hood climbing team
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What model phone do you have? I've done a lot of testing on this with several and can't find one that will do this. With no signal, they would attempt to send and fail. I could manually try to resend the message over and over until I had a signal but they would never automatically resend when a signal came up. Cell signals here in Idaho can be very spotty so this would be very useful.

last time I tried was with a qualcom phone. The cheap LG ones we had didn't last long enough to test it, I still need to try with the new phone, haven't been in an area without service yet.

Most Modern Phones have the antenna built into the body of the phone. Ancient phones like the Ericsson SH888 (my first phone 1998 ) pictured below have an external antenna.



A trick to increase the antenna gain would be to get a old coffee tin can or something similar and at the centre of the base of the tin a small hole large enough just to insert the cell phone antenna would be made. Pointing the tin and cell phone at the base (just slowly rotate through 360 degrees at the highest available point until the signal strength meter indictated the highest signal strength) would dramatically increase the cell phones range.
Its a similar technique to the long distance mesh networks being created in Africa.
Sadly though most phones do not now have external antennas.

This is the best and most to the point reply yet....

You'll save much-much more if you can turn off the screen back light. I believe the phone will last longer with BT headset because the screen is completely off when you use it (though BT itself will consume some additional power).

Regarding the aGPS feature. It's useless in the forest compared to the real GPS. You will need at least 3 towers in range (such an overlapping is rarely used in rural regions) to use it and they are all near the horizon. The GPS satellites are always above you head, just find a bit more open to the sky place. However, Hacksaw is right, aGPS may beat the real GPS in urban jungles - no doubt.

Also I've heard that it is possible to improve the reception with aluminum foil reflector. Though only used the foil once to _reduce_ the signal strength in close proximity to the powerful tower in the park (it was a rare problem with strong signal interference with it's own reflections).

There is a solution for the cars:
http://www.repeaterstore.com/products/repeaterkits/wilson/40db-vehicle-801201.html
In fact it's a wireless repeater (no wire to the phone antenna required).

They have even more portable devices: http://www.repeaterstore.com/products/repeaterkits/index.html

Those button sounds don't take that much battery life, they are coming from the same tiny speaker as the voice. I never turn mine on though since they are just annoying.