Dvorak has an interesting column up on orphan data formats and the lossage that comes in their wake:

Curiously, the apex of lost media is in our own era. The problem cannot get worse than it is. The irony is that this is an era where unprecedented technological revolutions are taking place, and yet we're losing important information. This has to be as tragic as the burning of the Great Library of Alexandria around 47 BC.

he gives some good examples, including mid 90's era digital cameras. The irony is, a 35mm camera that you bought 20 years ago is still useful.