We actaully stand a chance of decreasing the number of phones we use, if Orange have their way. They've launched Unique Phone, which works both as your mobile when you're away from home, and as a landline when you're in range of the Wifi network where you've installed your Orange Livebox. That means one bill, one handset and one number.
The phone will automatically switch between networks without interupting the call, and it's currently compatable with the Motorola A910, Nokia 6136 and the Samsung P200. It's going to be available from November, although you can pre-register your interest here.