I'm looking for a set of earphones that will fit underneath a motorcycle helmet.. here's the issue.. they cannot be sealed. Open-air type are fine and allow me to ear all that I need.. right now I'm using the earbuds that came with my zen micro... but they have a piece that goes straight down that gets caught on my helmet when i take it off...
I'd be careful with a non-closed type ear bud. In-ear phones (any headphone really) can cause hearing damage if the volume is too high for prolonged periods. It seems like on a motorcycle you'd have to turn up the volume pretty loud to make the music audible over road & wind noise.
Just a thought... your hearing is important!
<edit> maybe the Sony EX51's. They are "sealed" but you can still hear the world around you.