Mette Marie and I got our 1 GB iPod Shuffles last tuesday.
An iPod Shuffle is a beautifully simple little thing, so simple that it lacks good navigation. You have to push next/previous and then listen to what you get to move around, so I'd say the 512 MB version is enough, you can't navigate 1 GB of music in a meaningful way like that; not even if it's large files ripped at a 256 kb rate like I do.
The effect of it is that you put together a playlist and stick to it, which is not a bad thing at all. Or you set it on “shuffle” and get a random sequence of tunes, I just don't like to listen to music like that. There's a reason the songs are in the sequence they are on a CD you know. And if there isn't it's probably crap anyway, also know as a compilation.
The headphones doesn't seem to be very good, but I can't say how much they are to blame before I've tried some others. I'd like a pair of Nike VaporFlight headphones—made by Philips—for their supposedly sweat resistant design, and a iSkin Shuffle Duo to further sweat- and rain-proof it. Some sort of belt-clip so I can clip it to my tights when running is needed, having something hanging around the neck is annoying when running.
Speaking of which; I had a great run today, I'm convinced listening to Koxbox Dragon Tales made me run faster. Techno, or “Psychedelic Trance Goa” as the teenagers call what Koxbox is playing, works like that for me.