I find it difficult to warrant, or see why someone would take their iPod touch out jogging. For myself, I would rather go the route of having an iPod touch for one use and a Nano or Shuffle for jogging or work use. However, owning a touch, I was lucky enough to be sent the Sport Armband Plus to test.
The band itself is made of this weave type material. It is comfortable enough, albeit a little wide for my liking. However, it is very adjustable and has a nice little capsule attached, that can easily accomodate a set of headphone.
The part where you put the iPod touch is great. It holds the iPod very snuggly, installing a lot of confidence. You definitely don't want this letting go of your expensive toy whilst jogging, and there is no chance of that happening.
Jogging is a sweaty business, so the fact that this is hand washable is very nice. I used a dampened sponge on mine, rather than immersing it is water and a lot of the marks came of very easily. So my intention is to clean like this and then give it a good wash every six months.
If you really want to jog with your iPod touch on full display, then this is a good choice. Otherwise, it might be a better idea to keep your MP3 player hidden.