8 data sources merged to one UK based map - This is a fantastic UK-based Google Maps mashup. I'll quote from the site: "This prototype, primarily for BBC Backstage demonstrates layering of live geographic data onto Google Maps. You'll need a fairly modern browser to use it, as it makes extensive use of DHTML and client-side XSLT." - The maps all come from Google and the data and content come from various sources including BBC Travel, WeatherPixie, Pocket GPS world, Geobloggers, GeoURL, Yahoo News, weather.comÂ®, and Flickr.
Ashes Farm Cottages shows you the future - Although not a widely applicable mashup to most visitors, I think this is the future of tourism on the web for B&B's, Inns, campgrounds etc. This map, integrated with a holiday homes website in the UK shows potential guests what they could find in the vicinity of the Ashes Farm Cottages. If you're in that neck of the woods, the place looks quite nice to stay in as well!
Digital pub crawl in Edinburgh - Something tells me that you don't need a web-guide to find a pub in a UK village, town or city EdinburghPubGuide has established one, and they've just integrated a search assist using Google Maps!