The docs for mutt in /usr/doc/mutt/PGP-Notes.txt.gz have a macro example
that you can modify to make GPG do the equivalent of an encrypt to self.

Take a look.

JLF Sends...

It seems like on Wed, Aug 16, 2000 at 12:11:20PM -0700, Mike Starke scribbled:
Orig Msg> One thing I haven't figured out how to do in Mutt is
Orig Msg> encrypt a message to BOTH myself and the recepient.
Orig Msg> 
Orig Msg> When I type 'p', it will prompt me for the type of encryption
Orig Msg> (e.g. sign, encrypt, both, etc), and if I have the recepients
Orig Msg> key she will just go down the road just fine. I would, however,
Orig Msg> like it encrypted to my key as well. I would hate to generate
Orig Msg> a seperate attachment and encrpyt the file on the command
Orig Msg> line with 'gpg -r me -r recepient -e -a file' (that is how it
Orig Msg> is done, isn't it?).
Orig Msg> 
Orig Msg> All bones are always appreciated.
Orig Msg> -- 
Orig Msg> V/R
Orig Msg> Mike Starke
Orig Msg> mstarke@mobl.com
Orig Msg> public key "http://www.neta.com/~mgcon/downloads/mstarke_public.txt"
Orig Msg> 
Orig Msg> chgrp -R USMC /home/*
Orig Msg> 

JLF Sends...

-- 
When I said to people to use PGP/GPG for all email they laughed at me
and said they don't use encryption because they have nothing to hide
or it was too hard to learn and use.
When the press released that the USA FBI Carnivore system and UK RIP bill
allowed for easily reading their email, they called me to ask for help 
configuring PGP and GPG. I laughed.                ( J.L.Francois )