I recently helped set up a friend's new Mac Mini, which doesn't come with a keyboard, mouse or display - instead you use your old PC keyboard, mouse (as long as they have USB connectors) and display with it. It's a good choice for those who might want a Mac, but are put off by the high price (especially considering the fact that nowadays a Mac is just a PC with the Mac OS X operating system). It also very small and comes with a remote control, so it's also great as a media computer connected to a HDTV.
I plugged everything in; set-up was very quick and it was ready to go in minutes. But then I hit my first problem.
I had plugged in a standard British PC keyboard, the sort that you get with any Windows PC sold in the UK. Despite recognising the keyboard, and having it set-up to use a British layout, it still gave me quote marks when I wanted the @ sign (and vice versa), and the \ key was in a different place. The problem was that it thought I was using the British keyboard supplied by Apple - the standard UK Windows PC keyboard isn't supported out-of-the-box.
Thanks to a helpful Mac user at work, I was pointed to Phil Gyford's excellent post on the subject - check out the simple 4-step instructions under the "Moving punctuation keys" section. If you've got a new Mac Mini with the latest version of Mac OS X, in step 1 you'll want to download Andy Pearce's keyboard layout file instead. In step 2, the new layout will then appear as "windows-uk" at the end instead of "British - Windows - 2".