You can test it by setting up a server (or *someone* sets up a server, and you connect) (replae *someone* with someone

*g*, sorry). After that you ask someone to tune in, and he/she will listen if everything comes trough... That's the way I mostly tested everything.
Multicasting isn't possible with the dsp plugin for winamp itself, but setting up the dsp plugin correct, you can webcast all the sounds on your pc. With that in your mind, you could use some kind of program as 'teamspeak', or what more ppl are used to: msn. Then you could talk to each other, and webcasting this conversation

. Oh, and this 'dsp plugin' is the extra tool used to connect to the shoutcast server.
I'll talk to Jos, hope he's in a good mood

.
Jochem