I bought an iRiver iMP-350 CDRW MP3 player. I love it. It'll skip eventually if you take it running, but it works ok. I like being able to use the CD format. I guess the non-CD format players are gaining popularity. I imagine they must be good for running and other bouncy sports!
I have the IMP-550 and its a sleek, good looking player. Sounds good too.
I bought it to jog with and usually run for about an hour. It worked fine for a month than started to skip. I tried using the attachment that allows a couple of AA batteries to be added to the internal power supply. Still skips some.
I have finally adopted the routine of walking a bit at the beginning of the jog to allow the buffer to fill, when it starts to skip (after 30+ minutes), I walk or pause again to allow the buffer fo re-fill. Usually I can get thru my jog with just the one stop.
I should point out that I use the shuffle option so that I never know which tune is going to be played. This may make it more liable to skip.
I'm on my second one (had the first generation 5gig until this xmas when I got the 40 gig!). Never had a problem with it skipping. Don't really know anyone else that has either. That said, I really only know one guy that actually *runs* with it, and his hasn't skipped either.