To commemorate the launch of 20th Century Fox Home Entertainment's first foray into 2D to 3D conversion specifically for Blu-ray 3D release, the movie studio has released a Limited Edition Gift Set version of I, Robot 3D featuring a life-size model head of Sonny, the star robot.It's so limited, in fact, that the set has sold out on Amazon.co.uk, being listed at \u00a3164.93 and above from marketplace sellers, and Pocket-lint had to get ours from Fox itself in the US where it is claimed only 4,000 were made.This perhaps also explains why ours came without the Blu-ray discs. Fox titles tend to be region locked and US discs would be useless in our players. Many people do have US players over here though, so if that includes you, you might want to have one shipped in. Will cost you, mind.For us, a separate addition of the UK version of I, Robot 3D will do just fine. We removed the discs from their slip case and put them in the dedicated slots at the back of the bust. Sorted. Yeah, you don't get the postcards that come in the dedicated tin, but we're not planning on going on holiday anytime soon.There's two things about the head itself that are mighty impressive. First, it is genuinely life-sized. When we visited Fox Studios to find out how the 2D to 3D conversion was made (a process we'll be revealing in full soon) we were also treated to a showcase of props from the original film. One of those was a full-sized NS-5 robot from the film, Sonny himself, if you like. We can guarantee, therefore, that the Limited Edition model is to scale.The second thing is that it is remarkably robust and heavy. Not only are the details impressive (albeit made of plastic on the whole, where the real one was metal and plastics), but it also really feels like a substantial product.As for its purpose? Well, it's really a collectible rather than actually have a useful function. As disc storage goes, it's not exactly subtle. But, stick it on top of the cabinet you house your other Blu-rays in and it'll both impress your mates and scare burglars. Job's a good'un.Just don't expect your other half to be so keen.