Just went round to Sainsburys to see if they had any of the bargain Magellan or TomTom units left. No suprise, they were out of stock but they did have this one available for a bargain £19.99 (Maplin appear to be selling it for £99.98!). As with the Magellan/TomTom deal, I think stocks must be limited and I believe this was the only one they had (Leeds Moortown).
It has a 4" widescreen display, 2GB of onboard flash and claims to have a built-in TMC receiver. The supplied navigation software seems a bit rubbish but the device does run Windows CE so I'm going to spend the afternoon trying to hack it to run TomTom.