The Lazy Commuter:
Cycling is not just for fit and energetic people. Lazy people can enjoy cycle commuting too, and you can do much to fit cycling into a Lazy Lifestyle:
Sometimes you just wont feel like doing a repair to your bike. A lot of emergency maintenance can be put off to the weekend if you have a spare wheel hanging around (complete with tube and tyre).
I run 2 chains, one in cleaning solvent, one on the bike. If the chain gets very dirty I just swap (using a power link). I dont have to start cleaning chains mid-week.
Keep some spares at home and/or work: Cables, brake blocks, extra tubes. You dont have to carry them, but when they need changing you dont have to hunt around for a bike shop.
Use a track pump for regular inflating. Use a mini pump (or CO2) for emergencies.
Have a Plan-B: know your bus routes/metro/taxi numbers.