There’s nothing like a breaking news event to show off the usefulness of Twitter. Today large swathes of the UK were blanketed in snow, including London (first worst snow in 18 years – that’s global warming for ya folks). But the Twitter feeds and mashups came to the rescue of anyone wanting real-time updates about what was happening. One of the most useful was that provided by Ben Smith who built UK Trains Disruption Alerts which Tweets alerts for 25 UK train operators via travel news feeds provided by a project from the BBC called BBC Backstage). The more fanciful but interesting Twitter mashup came from Ben Marsh who coded the #UKsnow Mashup, pictured. This is a Google map which maps reports of snow from UK Twitterers. They simply Tweeted the #UKsnow hashtag, the first half of their postcode and a score out of 10 for their local snow cover. The resulting map did what a billion-dollar weather satellite, hampered by cloud cover, couldn’t – actually portray a reasonably accurate picture of what was happening on the ground.