Didn't get the greatest night's sleep, so I took it easy...and I love that taking it easy gave me a time that matched my 2nd best (33:01 total, 10:32/mile)! My faster runs the last couple of times must have helped my endurance.
My dad came along, and he has a Garmin GPS watch. It said we went a little further than 5km, so my route may actually be a little longer than I'd thought. I'll keep using the distance from dailymile's mapping software until I get my own Garmin (are you listening, Easter Bunny?); then I'll start using its data.