Saw these in At-Bristol's shop reduced to £6 ( these are £8.50-£10 elsewhere online, but obviously this deal is only good for those in or around the Bristol area). Good price for a cool item - suitably sold in many of the various gadget shops.
At-Bristol shop info: http://www.at-bristol.org.uk/shop
Product info: (from http://www.lazyboneuk.com/products/Eco-Cup.html)
Following the succes of 'I am not a paper cup' you can now get the Eco Cup. It's pretty much the same thing but the Eco Cup is a single-walled (non-thermal) porcelain cup with silicone lid and sleeve.
Stop using disposable cups for your coffee! Great for the whole office, our Eco-Cup is a porcelain cup with silicone lid and heat-protective sleeve.
The silcone lid can withstand temperatures of up to 230 degrees celsius (446 F) and helps keep hot beverages hot and cold beverages cold.
The porcelain Eco Cup holds approximately 450ml of your favourite beverage and the silicone sleeve will ensure your fingers don't get burnt whilst enjoying your drink.