Belkin (F8Z081EA) Sports Sleeve Case for 30GB iPODs is £6.49 delivered @ Dixons.co.uk (1/2 price)
Same item is sold @ JohnLewis for £12.95 + delivery. Also available @ PCWorld for £6.49 to store collect.
Product Information : Keep your iPod safe, secure and stylish with this form-fitting silicon sport sleeve from Belkin. It's designed for use with the 30GB iPod Video.