Do I need a case for my iPad 2?

I can't decide between the Origami Sleeve, the Speck FitFolio, or just going naked (possibly with an invisibleSHIELD). I'll be using it as my primary computer, so it should see a lot of use. I'd be open to other options too, but preferably something I can find for sale in my small town...I'm going on holiday in a few days and want to have the case/sleeve/screen protector by then.