In reply to Dominicandave:
Have a look as the Asus X102BA. I just bought one with exactly the same requirements as you. It's very small, well built, battery life is ok (4 hours), doesn't seem to heat up at all plus the fan vents are on the side not underneath, 500gb HD, 4gb ram, touchscreen if you're bothered, about £200 with windows and office.
Mine hasn't missed a beat so far, I'm really happy with it. Performance wise it's not gonna set the world on fire, but for films, internet browsing, word/excel, emails it's perfect.
I spent ages trying to narrow this down (if you want a tablet, they're worth a look as the choice is massive), but apparently these small simple laptops are called netbooks, so try searching for that too.