I use Vim on my little Asus eeepc to do my writing on the train. As I only write text or html, it’s been fine. But little luxuries like highlighting miss-spelled words are nice. I just found out that Vim supports this. Here’s the lines to add to your .vimrc:
setlocal spell spelllang=en_gb
There’s loads of help on the feature if you type :help spell inside Vim. But here’s the basics: ]s will skip to the next word that it doesn’t know about. If it needs to go into your custom dictionary, zg will add it. And in graphical mode, you can use the mouse to suggest words. Lovely.