Terminal 4 is a bit of an embarassment compared to the rest of Heathrow. The shops and other facilities are minimal in number, diversity and utility. Comms is also fairly rubbish - despite sitting under a sign that said 'wi-fi hotspot here' i couldn't get any connectivity. For those with more perserverance, there's apparently a T-Mobile and a BT hotspot. Both offer powerpoints and seats accordingly for the wi-fi minded in their respective areas.