I used this for my 80gb Zune. The zune fits great in the arm band, but the only thing was the the arm band is made for people that have very small arms. I had to buy a velvro strap to extend the band length, but after that is perfict for what I have been using it for.
This is definately a nice sturdy work out band for my iPod. I was worried that it would be too big for my 30 gig but there's a velcro piece that you pull down over it and I can make it hold my iPod in as tight as I need to; the 30 gig fit great. The only thing that bothers me about it is on the arm band part, there is velcro on both sides which doesn't make a difference when I'm wearing it, it didn't snag on me or anyhting, but when I stick it in my purse the velcro rips at the inside of my purse a little. Other than that, I love it!