I use the Zwift program (www.zwift.com) and think its pretty cool - you enter a 'game' whereby you are riding on courses in fictitious places and can interact (if you want to) with other riders. You can spend your time just riding or doing a structured workout by yourself or doing a race or group ride. You can buy 'smart' turbo trainers which automatically apply resistance to mimic gradients etc which improve the experience. if you are 'time poor' its a thoroughly good way to train - a bit like going to the gym. An added bonus is that you dont have to go cycling in the rain
Try it out -you can just watch other riders if you want - also, i think you get 2 weeks/50 miles free before you have to sign up...