This is actually a nice contact form with no frills which is just what you need sometimes. However, there are a few flaws to it. The main one in my view is the fact that it loads scripts onto every page regardless of whether the shortcode is used or not. This is pretty easy to solve and I have hacked it not to do this so if anyone wants that version then let me know. Or you can look at scribu's tutorial and do it yourself : http://scribu.net/wordpress/optimal-script-loading.html
Also the css is loaded inline which is kind of sloppy and has validation issues. Obviously it would be nice if the css was loaded conditionally too but because the css file is so small I think the penalties in doing that are actually greater than just loading the css file - but I am not sure.