In reply to James1982:
> Don't mean to hijack but would be interested in hearing people's more expensive, better quality recommendations as well as the cheaper options as I'm also in the market for some that won't fall out (but that also sound good). I get particularly sweaty ears, which is nice.
I think high fidelity audio is something that should be low on the list of priorities - yes it needs to sound decent, but chugging your way through 30 hours of ultra is hardly the time for appreciating the finer nuances of the music. You need something that is rugged, won't fall out, won't be uncomfortable after contnuous use etc.
I've tried a few - I prefer the style of ones that loop over the ears and round the back of the neck - they don't fall out, don't need to be as tight in your ear to be secure, and you can quickly pull them off and have them round your neck for a few minutes rather than having wires dangling everywhere.
http://www.amazon.co.uk/Sennheiser-PMX-680-High-Performance-Headphone/dp/B0...
I found the Senheiser ones OK, but the wiring to one earphone stopped working after a few weeks (I was only training running to and from work, so they weren't getting too much hammer). Senheiser customer support ignored my repeated emails so I'm not getting a replacement.
http://www.amazon.co.uk/Philips-SHQ4000-10-Headphones-Anti-Bacterial/dp/B00...
I bought a pair of these as an emergency purchase at Gatwick airport and used them on an 85km ultra in France - they were great during the race, fairly comfortable, very lightweight etc. However they're quite delicate and I've had to secure one of the earphones with gaffer tape.
After all that, I paid £5 in SportsDirect and bought some crappy pair Karrimor or something headphones in a similar style - they're doing OK, comfortable enough and cheap enough that I don't mind trashing them/binning them if necessary.