What are some unique ways you add exercise into your day?

I've just started recently, but I'll do vertical pushups on the wall a few times throughout the day at work, usually 3 sets of 10 at a time. It only takes a minute, so it's easy to motivate. I've also just begun to sit on a balance ball instead of a chair, but it's too new to say if I love it or if it's helping or not yet.

Here are some tips from a fitness pamphlet I'm hoping to get published this summer:

trade in your chair for a physioball
go for a walk at lunch time
go for walking meetings
keep small weights on your desk and if you have reading, conference call, or 5 minute break, do some arm exercises
keep resistance bands or ankle weights to do simple quick exercises

take the stairs twice
be fidgety, stand often, walk the long way

make it fun too