The image on the right is a space invaders scarf. But it isn't any old space invaders scarf - that barcode-style square pattern on the end is a 'QR code' ('Quick Response' code) and if you scan it into your mobile phone you'll get a surprise message: "Game Over!" or, by scanning the code on the other side of the scarf, "Insert coin for extra life."

It's pretty nerdy stuff, but since retro games and 80s graphic fashion is all the rage, the QR Code Scarf (a collaborative project between Kaywa and Office Lendorff) apparently hit the fashion market at just the right time a year and a half ago when it first went on sale. CEO of Kaywa, Roger Fischer, says that they think they've just about sold out of the 500 scarves they produced, with the first 300 going within the first month. Not bad for an incredibly niche-interest product.

But QR codes are starting to get noticed, and with the proliferation of mobile phones which can scan them now well established outside of Japan, pretty much everyone has the ability to 'unlock' whatever is hidden in any one of the unique codes. And those codes could appear anywhere; from clothing to murals or product packaging. In fact, these are exactly the sort of places where QR codes have been cropping up over the past year or so with much greater frequency. Additionally, scanning one of the codes can do a lot more than bring up a hidden message. You could be given the option to visit a promotional or informational website, or even start downloading a secret application for your phone. The possibilities are endless.

We wanted to look at fashion first, though, since on first impressions a QR code isn't exactly the most aesthetically pleasing of monochrome designs. Despite that, the fashion industry has been flirting quite convincingly with dainty square patterns for a while now. Roger Fischer at Kaywa says he was originally inspired to put a QR code onto a scarf after his wife bought one of the pixelated designs weaved into hats, scarves and wallets by collaborator Office Lendorff. Since the idea was fairly novel at the time, Kaywa and Lendorff (who quickly formed a partnership) decided to keep things simple, and the reward for scanning the QR code on the scarf is being able to read the secret geeky messages quoted above.

"You could go further," Fischer commented, "and make a space invaders game which could be downloaded via the scarf, but what we did was more of a fun, simple project. The idea behind putting it on a piece of clothing was to bring QR codes onto the street and make them more accessible."We thought about doing more clothing like this, and we have enquiries about it now and again, but the problem is we can't do one-off scarves or hats - it's too expensive."

One group that does do one-off, customized QR clothing is German designer emma cott. Via their online shop, you can order a t-shirt or sweater with a big, eye-catching QR code on the front which is uniquely designed to direct anyone who scans it to your social network (e.g. Facebook) profile, or even your latest eBay auction. It's a new form of self-advertising which plays on the immediate novelty of QR, but doesn't take the format much further than slapping a personalised code on a white t-shirt. Where Lendorff-Kaywa's scarf played on the digital aesthetics of the space invaders in-game graphics, emma cott has gone in the other direction and maximised the functionality of the codes over more adventurous visual design.

Very recently, Japanese designers SET have been specialising in QR design, announcing in the past few weeks a marketing scheme with Marc Jacobs in Japan to drive traffic to their new mobile website via strategically-placed QR codes. Also, the QR designs being popularised by SET are unique at the moment in including coloured cartoons or characters right in the middle of the blotches of black and white squares. This is actually very difficult to do so that the code is still scannable - you have to make sure no vital part of it gets lost behind your mascot otherwise it might look interesting, but it just won't work.

Meanwhile, Kaywa's latest project has nothing to do with fashion, but is a series of QR codes for a Chinese tea company, Shui Tang (see below, top).Scanning the QR codes on the packaging for each tea will tell you more about it, allow you to place an order for more or see what related products are for sale. And there's an awesomely-designed hotel in Dubai whose exterior design is one massive QR code (see below, bottom). Might be tricky scanning that into your Nokia, though.

Update! Roger Smolski, QR code blogger, sent us this charming picture of his dog wearing Lendorff-Kayway's QR code scarf. Adorable.