Floating Sequencer Charges
Note: To do this trick you need to be in a level where there is a force field that you can turn off. Have some Sequencer Charges on hand and save the game. Turn on the force field and set the Sequencer Charge on it using secondary fire. This will probably take some of your shields. When the charger is set, run over to the switch and turn it off. Move back and you will see that the Sequencer Charge is floating in mid air.