I use Ventrilo for voice-chat. You just join a server, and you can talk to as many people as your server supports...we typically have about 10 friends in there regularly, I have no idea how many the thing can actually support though without lagging or something.
But it's great for playing SSB64 online, it'll be great for Brawl as well. My friend pays for the server though, so you'd have to find a Vent server or pay for a private server...something like $10 a month I believe.
LEFT4DEAD411.COM
Bet with disolitude: Left4Dead will have a higher Metacritic rating than Project Origin, 3 months after the second game's release. (hasn't been 3 months but it looks like I won :-p )