"Two way messaging smart Igate for HF APRS over PSK, QPSK and GMSK."
http://www.crosscountrywireless.net/aprs_messenger.htm
I have been looking for something like this for HF for ages since I am intrigued by the idea of being to able to message to one central place on the Internet in case of an emergency
http://www.findu.com/cgi-bin/emergency.cgi