The London Marathon is on Sunday. Check out the excellent interactive map to find out where and when to watch. Here's the times for watching the runners from Creekside and Creek Road: 9.40am Elite women; 9.45am Wheelchair racers; 10am IPC runners; 10.35am Elite men; 11.05am Mass race
If you know someone who's running, it's quite feasible (we've done it) to cheer them on in Deptford, then jump on a train (if they're working) and cheer them again at another part of the course. More 2013 race information here (including details on road closures).
Oh, and please wear red and hang a banner to save the NHS and Lewisham Hospital if you feel so inclined. It's a photo opportunity.