I have been making little holders, cozies, covers for umpteen IPods and various Cell Phones for quite some time on special order and having them available at craft fairs. Some of the folks who ordered sent me specific dimensions. I've made these in machine knit both standard 4.5mm and bulky 9mm and also hand knit and crocheted. It's been an interesting line of crafts so I've decided to share all this research here online with anyone who cares to use it. It will help your sales if you mention some of the various sizes your covers / holders will fit. Enjoy!

iPod Digital Audio Player, MP3, 20GB
Height: 2.4 in
Width: 4.1 in
Depth: .57 in
Weight: 5.6 oz
iPod mini Silver Digital Audio Player, MP3, 4GB
Height: 3.6 in
Width: 2.0 in
Depth: 0.5 in
Weight: 3.6 oz
iPod Photo Digital Media Player, MP3 / Photo, 60GB
Height: 4.1 in
Width: 2.4 in
Depth: 0.6 in
Weight: 5.9 oz
iPod Photo Digital Media Player, MP3 / Photo, 30GB
Height: 4.1 in
Width: 2.4 in
Depth: 0.6 in
Weight: 5.9 oz
iPod Shuffle Digital Audio Player, MP3, 512MB
Height: 3.3 in
Width: 0.98 in
Depth: 0.33 in
Weight: 0.78 oz
Apple iPod+hp Digital Audio Player, MP3, 40GB
Height: 4.1 in
Width: 2.4 in
Depth: 0.69 in
Weight: 5.2 oz
IPhone
Width: 2.4"
Height: 4.0"
Depth: .46"
Weight: 4.8 oz
Samsung a670 Cell Phone
Height: 3.3"
Width: 1.8"
Depth: 1.0"
Samsung a650 Cell Phone
Height: 3.3"
Width: 1.8"
Depth: 0.9"
Samsung x427 Cell Phone
Height: 3.3"
Width: 1.8"
Depth: 0.8"
Nokia 6620 Cell Phone
Height: 4.28"
Width: 2.29"
Depth: 0.93"
ZunePhone
Width: 2.1"
Height: 3.1"
Depth: .48"
Weight: 3.9 oz
Nokia N-Gage QD Cell Phone
Height: 4.65"
Width: 2.68"
Depth: 0.87"