You don't need one, most students do not have one and do just fine, but they are nice.
I just finished my first semester (BSN) and didn't have one and did fine, made A's and got excellent clinical grades. I also work as a nurse tech.
I plan on getting the Palm TX this month! I just think it would be much more convient to carry around the smaller TX than my drug guides, etc. Sometimes I wanted to bring certain books to clinical like Ackleys, Davis, med dictionary but I just didn't have the room to carry them all--who does? So for me, it's a matter of organization and less room and I like gadgets
Plus sometime at my job there is some downtime (depending on which floor I'm on) and it would be nice to watch videos, tv shows, study NCLEX questions, etc to be honest.
I also think it would be great for me personally to have my calander on me because I am forever forgetting something!
So if you have the money to spare I would say go for it, I know I am, but if you are broke it is not necessary.