A big word up to The Evil Pixie. Run whenever you can. Whatever you do, it's GOTTA be better than sitting on you butt and pushing the accelerator every few seconds.
Run to work (keep a change of clothes and an eye for places to change), to meet up with a friend (a good friend who will forgive you for being sweaty when you arrive), at lunch, going home, on your way to the gym. Heck, combine it with cycling every other day, or walking part of the way.
I live and work in East London, so I naturally find that running is the fastest (except for bicycling), cheapest, most interesting way to get where I need to be. Now, I'm no fanatic and I have to take my kids to school on the bus, on a train or in the car, as well, but I really, really look forward to running and/or walking whenever I can.
As for running before or after eating, I have read so many pieces of "you HAVE to do it this way" advice that contradict each other. All I know for sure is that it's good to have plenty of water before and after your run (but not so much before the run that you're going to be desperate for a pee in a few minutes), and sometimes I like to run an hour after a solid meal, and sometimes I like to eat after a big run.
Oh, and, chocolate, ice cream and red wine ALWAYS taste better after I have done a long run on the weekend.