OR:
Sennheiser CX 300 - B (black).
I got these 'B' grade
here for £6.47 delivered (they can be cheaper) They normally sell sub £30. If you're bothered you can get them in white too - more expensive though. I'm happy with them and they fit comfortably in your ear and don't fall out.
Specifications
* Powerful, bass-driven stereo sound
* Supplied with three different sizes of ear adapters for a perfect fit
* Excellent attenuation of ambient noise
* Extremely small and lightweight
* Ideal for use with all MP3, CD, DVD, MD players and portable game systems with 1/8" (3.5 mm) headphone jacks
* Asymmetrical cable
* 2-year warranty
* Frequency response 18Hz - 21kHz
* Cable length Asymmetrical, L: 170 mm
* R: 510 mm, (850 mm divider to plug)
* Impedance 16 Ohm
* Sound pressure level (SPL) 112 dB (1 kHz, 1 Vrms)
* Jack plug 3,5 mm stereo (angled)
* Ear coupling intraaural (ear canal fit)
* Transducer principle dynamic, open