WPMU has given us an interesting insight to the world of 'free' Wordpress themes that seem to populate the web. Where many excellent (and pretty damn decent ones) can be found on the likes of http://www.smashingmagazine.com and http://www.speckyboy.com, there are also a fair share of places that generate what can only be described as link farming.

Like software downloads, a few of these even contain malware, so it's crucial you are certain what you're downloading is legit before hosting it on your own server.

One major thing WPMU points out is ensure you avoid anything that includes Base64-encoded sections - the video and link above should give you some key pointers of what to watch out for.