Linux Tips: Vim autoconfigure for different filetypes

Thanks to Ajay Somani, over at http://ajayfromiiit.wordpress.com/ for this post that finally helped me solve a long term gripe with vim.

When I'm in 'programmer' mode, I use vim with syntax highlight turned on.
When I'm in 'wannabe fiction writer' mode, I use it with spell check turned on.

And these two personas keep fighting like Jekyll and Hyde. Because I have both of these turned on, vim insists on syntax highlighting my fiction, interpreting apostrophes as quotes and then coloring everything after them. Worse still, it spell-checks my C-code. It'll highlight some text in red, and then spell-check it, and decide it's mis-spelt, and thus surround it in a background colored.... red. This results in large blocks of red-on-red text that cannot be... uh... read.

The solution, it turns out, is to add this magic line to my vimrc:

autocmd BufEnter *.txt set spell