Koss's CC_01 earbuds replace those easily-lost foam or rubber tips with an expandable and contractable system. Just turn the metal screw top on the back of the 'buds, and the tips will adjust to fit.
Koss is a pretty reliable manufacturer of low-cost eargear, so it's a little surprising to see them challenging the big boys with earbuds that clock in at $US150, but perfectly adjustable fit is a great idea. Let's hope the sound quality warrants the price. The Koss CC_01 will be available this March. [DVICE]