These iPod cases, made from cassette tape shells and 45 record vinyl, are commercial items, which cost US$45 each, but it'd be a cinch to replicate something similar, if you'd rather roll your own.
45 Nano Cases - [via] Link
Related:
- HOW TO - Vinyl record table lamp - Link
- DIY Dali vinyl record clock - Link
- Glasses made from vinyl records - Link
http://blog.makezine.com/archive/2007/09/ipod_cases_inside_of_cass.html