If you define a remote fishing location as one where there is poor cell phone coverage, you may want to consider picking up a cell phone booster.  When I lived in Chesterfield outside of Richmond, my home was in a dip - no coverage.  I solved this by buying one of these Smoothtalker rigs.  It can plug into the wall or your car and boosts your power by 3 Watts.  My reception went from "no service" to three bars as soon as I plugged this puppy in.  You may be able to get similar improvement with an external antenna.

I have found this to be handy up in the Shenandoah and the other hinterlands of the tri-state area.  Without using this when fishing the 'doah, I cannot get a signal on Verizon until I get back to Warrenton.  With it, commo's not a problem.  Beyond the obvious safety reason for needing good commo, there is the "keep the wife happy" reason.  The Basswife if ok if I am going to be late getting home as long as I give her a call and let her know.  This results in a higher number of "kitchen passes" to wander off for trout.  As tough as some of us guys talk, you've got to admit that if "mama's not happy, nobody's happy".  If a phone call with make the Basswife happy, that's a no-brainer - although stopping at Safeway on the way home every once in a while and picking up an $8 bunch of flowers helps as well!

The key to making this thing work is to find your external antenna connection.  You cannot rely on the advice of the guy in the cell phone store.  I just had to move from the Motorola phone shown here to an LG and was told it did not have a connection.  When I got home, I noticed the rubber/plastic plugs on the  back and, when I pried the big one off, it revealed the external connection.

Since so few people are even aware that most phones have this feature, it's not surprising that the sales guy was unaware of it.  The best way to find out if your phone has a connection is to go to this page on the Smoothtalker site and see if there is an adapter that will allow the booster to plug into your phone.  If there is, then you have a jack somewhere!

Smoothtalker setup

I have seen other models advertised elsewhere.  A quick Google turns up this site which advertises wireless repeaters - sounds like a nice solution that avoids the need for a cable.  However, I have not personally used this technology, so be sure you check it out.

Important!  You may not need to get an electronic booster - you may be ok just with a better external antenna - these are much cheaper - one shown below.

I know the stuff shown here works.

And.  I know that that little "antenna" thingy that you stick in your battery compartment does not work.  That was a waste of 15 bucks when I tried that solution back in 2001. 

I just did a quick scan of the Consumer Reports website and, unfortunately, they have not done any studies on these technologies.  We're on our own here.

Find your antenna connection.  Based on my experience with the Motorola and LG phones I have, it's a little plug next to the antenna tower

This is a picture of the antenna - separate thing from the Smoothtalker.  It will also boost your ability to receive and transmit. 

Here's a link to a series of pages that explains how these antennas work and the best way to use them.