Small doses of exercise?

I've recently jumped back on the health wagon but haven't been able to commit myself to starting a real workout regime yet, (not a lot of spare time during the week, and lets be honest, not a lot of energy) so I've started doing small things to move more. That includes some yoga in the morning, taking the stairs and not the elevator at my office, and I've stopped sitting in a chair at my desk and now stand instead (it works out to about 7 hours of standing.) Does anyone have any suggestions of small bits of activity I could fit into my day?