ypsi~dixit has an interesting post that contains a computation of how many punch cards it would take to read an MP3. The answer?

"Assuming a non-Hollerith encoding with eight bits per column, and an MP3 file encoded at 128kbps CBR, there would be 36,864 cards in that deck, and the card reader would need a throughput of 205 cards per second. It might be wise to include an 8-column sequence number, however, so that a misordered deck can be repaired by a card sorter; with 72 data columns per card, the total is precisely 40,960 cards (40K cards), requiring a 228 card/second throughput." The 21 boxes of cards needed would by 5 feet 9 inches tall.

Punch cards are before my time, so I can't claim any direct experience with them. My earliest storage technology was cassettes on a ZX81; now that was high-tech! ;-) I have to agree with his closing thought: "That such a huge leap in technology is well within living memory astonishes"...