Between Skype, Google Voice, Viber and several smaller players, there are plenty of platform-agnostic services vying to put your voice through their IP (get it?), and now UK carrier O2 is introducing us to its twist on multi-device communication with TU Go. It's like a marriage of the traditional phone service with the idea of making calls on your laptop, or sending messages from your tablet. An evolution of parent company Telefonica's similar TU Me apps, the TU Go software spreads your phone number across up to five devices simultaneously. You can make and receive calls / texts and manage your voicemail from compatible kit with a cellular or data connection, with all activity aggregated into one "timeline." You can't hook your smartphone up to WiFi, or gab away on another device to avoid eating into your plan's allowance, though -- all usage is treated as if it originated from your phone. TU Go is now available to all O2 customers on a monthly contract, and if you want your whole house to ring at once, head to the link below to find apps for iOS, Android, and a beta for Windows 7 (note: it really is 7-specific, and won't run in Windows 8).