MP3 on Small CDs (Score 1)

Is there anything to stop some manufacturer making a small MP3 player that reads from these small CDROMs. The unit should end up being just a bit larger than a minidisc player. We could then place hours of music on these small CDROMs. Would the drives be able to spin fast enough? 4MB for a four minute track, 1MB a minute, 18kbytes a second? Would the power consumption for spinning the CDROM and decompressing the data be too great?