When playing as the Tech online, switch to your grenade launcher and use your primary fire on an enemy turret to easily take it out. This also works on enemies, but not as well. Also, if there is a room with people crowded inside, use the secondary fire with your grenade launcher to gas them all. Fire about two shots in the room to take them out.

This can be done with any character as long as the person you are telefragging is on your own team. When you go up to revive someone, immediately after you revive them press Crouch to telefrag them. Note: You will lose points.