What if every call you answered, every text you sent, and every Facebook status update you posted actually worked to improve your fitness? It's kind of a ridiculous notion, but the ToneFone—which is basically the heaviest case you'll ever slap on your iPhone—offers just that.
So how does it work? It's heavy, and that's pretty much as technical as it gets. Available in 1kg or 1.5kg versions the ToneFone is made from 100 per cent British steel and is rubber-coated to prevent it from slipping out of your sweaty hands after a brutal workout checking Facebook and Twitter.
The heaviest version will set you back £25.40, and since the novelty of keeping this case on your phone all day long will soon wear off, you'll probably want to get one for the home and one for the office to keep up your workout routine. [DesirableBody via The Gadgeteer]