Should I get a tablet or a regular notebook?

I was wondering if anyone had some input for me. I'm looking to buy a new computer for the fall. I want something that's portable and lightweight with a good battery life. I need it to be relatively fast. I don't really care if it's a flashy notebook- price is also relatively important. Now, I know that tablets also function as regular PCs, but that the screens can be grainy. However, as a college student, I'd love to be able to take notes and draw diagrams in science cles. Also, the Wacom tablet would be so useful for photoshopping. But tablets do have drawbacks... Any ideas?