In one campaign I'm running (with two of the four players new to RPGs), each player has two PCs, and all eight PCs are part of a unified team of the Adventurers Guild in their city. (It's Greyhawk City for the sake of my own convenience, although it's a somewhat modified one.) Each Guild member wears a ring that can be used once per day to teleport back to their Guild HQ. Furthermore, within several rounds of someone teleporting in to the Guild HQ, if another member of that Guild team (whose rings are all part of the same set) touches rings with the one who just teleported in, the ring "traces the teleport" and allows the PC to teleport over to where the other member just teleported in from.
So, the end result is that if a PC gets himself into too much trouble (low on hp, out of spells), he can "bink" back to HQ and be replaced by that player's other PC. The same holds true of PC death, generally -- a dead PC can have one of his partners activate his ring for him, sending the corpse back to Guild HQ (to be resurrected behind the scenes, although the cost is paid by the dead PC) and allowing the player to bring his other PC into the battle. The only time this wouldn't work (which thankfully hasn't come up in the campaign yet) would be if the slain PC's body was somehow inaccessible to the other PCs.
This setup hasn't fully taken away the sting of death -- it's always a bummer to have a PC killed -- but it's done wonders for keeping the players active during a gaming session.
Johnathan