you're a trooper.
until you decide on which walking DVDs to do, here are some easy/free ideas:
1) get any cardio video you already own and just walk to it. dance videos are really good for this purpose.
2) youtube has MANY walking videos, full length even, from Leslie, jessica, and i'm sure many others. Leslie and Jessica have pretty much cornered the market on walking videos on youtube.
3) before investing in a treadmill, and especially if space is a concern, a rebounder would be great! don't need a fancy schmancy one - i got mine from a garage sale for $4.
4) for air-conditioned walking, take to the mall and bring the kids along. stroller or no stroller works good.
5) if you must walk outside, protect yourself with sunscreen, a hat and an umbrella (portable shade).
6) vacuuming in the house uses lots of steps.
7) if you take the kids to the park, they can play while you walk circles around the jungle gym equipment.
good luck!