Its more of a wanted need than a needed want.If you plan to study something related to graphical arts or law, believe me you WILL need your own computer.
I'm still using the family computer, which is a real pain. I can't load any new programs on this thing or else it'll have a heart attack, and there's really no more space to load any programs I want to load.
I really want a laptop to that I can load programs to enhance my art works, and to make my webcomic even better. But I also need it for when I got to college.
Other than internet surfing and watching vid.s online, that's pretty much all I need a laptop for. @_@
I recommend getting a laptop, since it will allow you carry and modify your work on the go when needed.
Also if you need some advice, you can easily show your teacher or classmates what's the problem and get the feedback you need.
Amongst many other etceteras.