Netbook or PMP

ive looked online but havent find much discussion between which is better.
im looking for somethign to fill my time on the long bus rides to and from university and so forth.
i realise that a netbook would be better for use at university, browsing word docs etc..
However on a 30 minute bus ride i wouldnt want to take it out and say listen/watch som,ething because of teh hassle.
Plus ive been looking for something that will last me battery wise so im uncertain.
any helps much appreciated thanx