Yeah, you don't need to be a Gnutella developer to join. I'm not yet (soon though) and I'm in it. But here is the entire list of hostcaches that I have my program use when I tell it to connect:

connect1.gnutellanet.com:6346
connect2.gnutellanet.com:6346
connect3.gnutellanet.com:6346
connect4.gnutellanet.com:6346
gnutella.hostscache.com:6346
router.limewire.com:6346
connect.cultiv8r.com:6346
xcache.cultiv8r.com:6346
connect3.bearshare.net:6346
gnet2.ath.cx:6346
204.83.201.2:6346
209.190.205.236:6346

You'll probably get something there to connect, it always works for me. There are other hostcaches out there, but I don't have a list of them.