FB>   I'd like to register FastEcho, but the site's registration
 FB> form points to a 404 error, and the Slash BBS seems unavailable.

yes, slash shutdown his bbs operations some time back, IIRC...

 FB>   Any ideas?

have you tried to contact the author directly? he is still listed in the
nodelist and his web pages are still active... if it were me, i'd contact
him and just ask him for a registration key and see what comes about...

try sales{at}softeq.de or tobi{at}softeq.de and see what happens...

i do know that real life and actual work/job stuff took over much of his
activities after he completed school some years back...

)\/(ark