Packet Radio [text-based email independent of the Internet]
Outpost Packet Message Manager program at http://www.outpostpm.org. Outpost is a Windows-based packet message client that lets you send and receive packet messages just like email using programs like Outlook and Eudora. Created by Jim Oberhofer KN6PE and works for 98/NT/2000/Me/XP/Vista, this program takes the pain out of packet.
Packet Radio Information on the Santa Clara County ARES/RACES website http://www.scc-ares-races.org/packet/index.html
Santa Clara County ARES/RACES Packet Frequency List at http://www.scc-ares-races.org/freqs/packet-freqs.html
Northern California Packet Assocation (ncpa) at http://www.n0ary.org/ncpa
Packet Sysops of Northern California BBS List at http://www.n0ary.org/ncpa/psnclist.html
Introduction to Packet Radio by Larry Kenney, WB9LOZ, at http://www.choisser.com/packet/
Superb site of Radio-to-TNC wiring diagrams at http://users3.ev1.net/~medcalf/ztx/wire/index.html
Digital Communications Virtual Library (includes packet radio primer and FAQ) at http://www.tapr.org/tapr/html/pktf.html
Local packet frequencies used by AD6RY:
Automatic Position Reporting System (APRS)
APRS website at http://www.aprs.org
APRS database archiving weather, position, telemetry, and message data at http://www.findu.com
International Space Station relays APRS reports from amateur radio operators around the globe at http://www.findu.com/cgi-bin/ariss/index.cgi
Winlink: Digital Messaging for Amateur Radio
Internet Radio Linking Project
Official Home Page of IRLP at http://www.irlp.net
IRLP at dxzone.com http://www.dxzone.com/catalog/Operating_Modes/Internet_Linking/IRLP/