removing a piercing once its COMPLETELY healed (usually 6-12 months for total healing) is fairly easy to do, provided its a piercing that's through normal skin, like navel, eyebrow, etc..., and the piercing will stay open for a few days without jewelry. You just have to put something slippery, like lotion or vaseline on the jewelry before you try to put it back in. labret (lower lip), nose, and tongue tend to close quickly if the jewelry is removed even after its healed, though.
if you're really paranoid with something like a navel pierce, an eyebrow or something, you can run the clear elastic jewelry beading string through it and tie it in a small loop so it is snug against the skin, but not tight. You can get this line at a craft store like michaels, the bigger the gauge, the better in this case (only comes in up to about 18 gauge, and the average piercing is 12 or 14 gauge). DO NOT USE FISHING LINE. Its coarse and can cut you if its pulled. (think of a cheese slicer here...ouch!). The jewelry line will simply stretch. I do this if I'm going to be on a long airplane flight and don't want to set off the metal detectors. Works well if you know you have to have x-rays too.
