Here's a neat idea from Jabra. The BT325 is a pair of earphones that you plug into your MP3 player, but also inside is a Bluetooth headset that you can use with your cellphone. It's smart, too, because when your cellphone rings, if you have a A2DP-enabled phone it stops the music and switches over to the Bluetooth device, letting you answer the phone call. The BT325 phones are water-resistant and can give you 14 hours of music or 16 hours of talk. When available, they ll be $120.
By the way, Jabra is also offering Bluetooth adapters for MP3 players including the A120s for players with 3.5 mm jacks, and the A125s for iPods.
CeBIT 2006: Jabra reveals new products for music lovers [Tech Digest]