Taking music on your travels is almost as important as taking a camera and credit card to me!
However, I don't know if I'd take the minidisc; mostly cause I wouldn't want it lost or stolen, and taking a charger is another thing to hassle around with.
I'd go for the discman and a few discs. Not the hassle if you lose it/drop it/ get it wet/get it pinched, etc.
Many people do seem to take portable music. I never have. I find that the soundtrack playing in my head is more interesting and varied than any MP3 player I could load up.
You will have many hours of waiting in many different places, your own choice of music will be an assett and acompanion, and with the added benefit of drowning out the awful stuff that you hear in so many public places, so go for it take an MP3 player.
Pack a couple of good waterproof bags and when necessary pack all your gear or just the valuable stuff in these bags inside your back pack, very useful when treking, and they do work even if you overturn when river rafting! You can get the best from military suppliers.
I would definitely take the MD player. I travelled with mine and it fitted in one of those amenity kits you get on long haul flights. Fitted charger, 10 MD's, player and adapter with some spare batteries quite well.
And if you get to MEL maybe change the music for free.
Im thinking about taking my ipod to oz with me next week but bit worried about charging it. It will be ok most of the time as it will be locked away but dont fancy risking leaving it lying around to charge!
Got that use to it think its too much hassle to cart a load of cds around!
Why not charge it at night while you are sleeping. I found I had a powerpoint very close by while in hostels and charged my electronics overnight in the safety of my sleeping space.
thanks for all your suggestions guys - i will pack everything up today, see how much space i have left, n how heavy my pack is - still havnt decided, but i might take it as it is quitesmall n compact, but keep your suggestions coming.