Configure wifi ssid and password for later use

[Jim]

I have a Raspberry Pi that I've set up to control an SDR and send the 
audio back to my Kubuntu box.  It has one of the RTL usb dongles that 
uses a chip originally made for DVB-T broadcasts.  I have Simplefm, a 
command line sdr app to play FM stations and Nrsc5 for HD radio, and VLC 
to stream the audio.  I also have an OpenVPN server on it.  At some 
point I'm going to ask a friend in Phoenix to set it up for me at his 
place and connect to his router.   I wan to make it as simple as 
possible for him to set up, just connect the antenna and plug in the 
Pi.  To do that I'd need to set it up to connect to his wifi.  Is there 
a way for me to save his SSID and password before I send it to him?

Thanks.