Count me in for another WATP girl. I do my workout so early in the morning that it's always still dark out, so it isn't safe to go out walking where I live. I do about 30 minutes (did a new DVD today, and it was only 25 minutes), which is 2 miles. If I don't get my exercise done in the morning (this happens about once a week when I just can't get myself out of bed at 4am ), I go out walking after work around my block, which includes some small hills and is about 3/4 mile per lap (and I usually get in almost 3 full laps in 30 minutes).
Of course, I'm not losing tons of weight by doing this. Walking doesn't help to cancel out pizza and other junk I shouldn't be eating