There are five key points to the success of such a scheme.

1. 100% of visitors will be scanning these codes on their mobile phones. The code must point to the mobile version of Wikipedia.
2. <100% of visitors will speak the language of the country where the museum is located (for example, 25% of visitors to the Science Museum are foreign. Pointing to just the English article is unacceptable.
3. The QR code should be simple enough to scan quickly. This mean using as short a URL as possible.
4. The URL presented must be human readable. The user must know to where they are being directed. The QR scanner may have a "history" option which will allow the user to see the codes they've scanned.
5. Statistics must be gathered showing how many people are using the QR codes to assess their effectiveness.

Mobile Redirection is Broken on Wikipedia

The current way that Wikipedia does mobile redirection is broken and should be considered harmful to users. At the moment, a mobile user-agent visiting http://en.wikipedia.org/wiki/Rossetta_Stone has to load the entire HTML document, process the complex JavaScript, and only then is redirected to the mobile version of the site.

This means that a visitor incurs a significant wait before they are directed to the correct content. If the visitor is roaming in a foreign country, they may pay significant per-MB costs for this download.

The correct way is for Wikipedia's servers to detect the mobile user-agent and 302 redirect to the mobile version.

Language Detection

I don't know how Wikipedia detects the preferred language of its visitors. Ideally, it should look at the Accept-Language Header of the phone and / or use the IP address of the device (assuming the user isn't using the museum's WiFi).

Finally, the QR/mobile version of Wikipedia should allow a user to easily change the language of the page they are viewing.

Short URL, Human Readability, and Statistics

URL shortening services often produce a jumble of letters and number which, while short, mean nothing to the human user. For example http://bit.ly/fNXn1W. In addition, use of commercial URL shortening services is problematic should the company no longer maintain its service.

Using the "normal" URL gives us this

Using the "mobile" URL gives us this

Using a QR code specifically for QR use gives us this

Finally, there could be a separate short domain for Wikipedia accessed through QR codes. For example, the currently unregistered qrpedia.org Obviously, this has branding problems - would people recognise it as being from Wikipedia?

Conclusion

Ideally, we would use a URL like http://wikipedia.org/qr/Rossetta_Stone

When the use scanned the code and requested the URL, Wikipedia would then perform two actions

1. Detect the user's preferred language.
2. 302 redirect to the mobile version.

If the language detection was incorrect, the user could simply change it.

Wikipedia admins, museum staff, and anyone else, would be able to see which exhibits had the most scans.

Thoughts?