I have those Sony ear buds. I like them for a couple reasons. For starters, they fit. I dont feel like I am going to rip my ears off when I take my helmet off. secondly, they sound good. I can keep them at a volume low enough to clearly hear the music and still hear the road. If I am stopped, I can pretty muych carry on a conversation.
BTW, I keep my MP3 player in the left chest pocket of my jacket.
Soren