Could this be the latest Sony Ericsson Walkman phone, a high speed 3G and HSDA enabled sliderphone - or is it just a clever mock-up?

Flagged up by Intomobile.com, this Sony Ericsson Walkman-branded device first appeared on a Polish auction site , which claims it is a prototype from the factory floor. It could be the mobile code-named Shinobu that has previously been discussed on Esato.com .

Specifications posted on the Polish site suggest that the 12.5mm thin sliderphone features 3G with HSDPA, and has a 2-megapixel camera onboard. Other details are understandably vague.