Way 1.
1. Put your weapon on your back.
2. Take a second weapon into your hands.
3. Log out.
4. Log back into the server.
5. The weapon is both in your hands an on the ground.
Way 2.
1. One player logs out of the server.
2. Just after he disconnects, another player handcuffs the character which will disappear in 30 seconds.
3. Take items from the handcuffed player's inventory.
4. Unhandcuff the character before it disappears.
5. When the player logs back into the game, his/her inventory is untouched.