30 minutes on a treadmill is boring, so yesterday I decided to buy my first MP3 player (a Sony) and naturally chucked away the freebie headphones. I planned to use my existing Sennheiser MX500's, but they are a bit too big for my ears, so when I saw the 'ear canal' CX300's (which everyone is raving about) for sale in the same store, I bought them too. However, they are definately NOT suitable for jogging. If you intend to buy them for the gym..... forget it! Stick with regular ear buds. Every step generates a loud thump in your head. After the first 30 seconds on the treadmill I had to take them out... it really isn't pleasant and I've got ear ache now. I imaging they'd be very good for sitting still on public transport (I don't use public transport) but they should be avoided for anything else. I also think the bass is too heavy and hard aswell. So although I'm a Sennheiser fan (I have a pair of the awsome HD600's aswell), I feel I need to redress the balance on the glowing reviews of these ear phones scattered all over the web. Although they probably are quite good for this type of product, I reckon other phones would be a better choice for most people. I imagine selling the CX300's would be difficult. Despite my fanatical ear hygene, the rubber seals have become slightly 'tacky'. I'm sure noone would fancy them second hand. I'm now looking for a pair of decent 'vertical' ear buds to see if they are better suited to the gym and my tiny lug holes. Any recommendations?