I need to get a portable music system powerful enough for a school hall and portable to drag in and out. Needs mp3/iPod.

Not sure if this is the right question for this type of forum, but I know Bose makes such a system, rumored to be 50-60 watts.

http://www.bose.com/controller?url=/shop_online/digital_music_systems/so…

or something with more wattage (75), cheaper, but only speakers:
http://www.amazon.com/Coby-CS-MP77-Performance-Discontinued-manufacturer…