Well okay.... not exactly!
But! On the PC you can launch one copy of the game 2-4 times and create yourself a LAN game with one client, and join all the other clients to the same game. Bam, perfect way to stash items away or powerlevel alts -- just create the game with the highest level toon you have (really L30+ to make it work well, 40+ is better) and join with the alt. Park the alt somewhere safe in a high level zone, then just start killing stuff with the higher level toon. XP is awarded anywhere on the board. I 'boosted' a friend's L1 to L20 in a matter of minutes. They also get weapon proficiencies based on what their active weapon is.
It's also a great way to tweak the difficulty or farm better items, I usually duo with a friend but we are each making some hunter alts with "team find rare item" and "team scavenge extra items" class mods to park in the game. 4 players makes the game MUCH harder than 2 players, we get a ton more "elite" (Bad Mutha in game terms) mobs spawning that already drop lots more & better loot, on top of the team mods helping out the drop rate. And if I'm soloing I can toss my extra character in the game to make it harder -- the default single-player game is I think TOO easy unless you are either playing over your level or have horrible gear.
P.S. I am pretty much addicted to this game now. If you haven't played it, pick up a copy so you too can "take a riiiiiiiide with the Scooter man !!!!"