If you're running either on roads/sidewalks or on trails that are visible from aerial photography, you can plot your course very accurately on mapmyrun.com .
Then a simple stopwatch can give you the rest of what you need to know. The timers in most phones have lap capability, if you have a way to make your phone's screen accessible when you run. If you have a smartphone, there's an iMapMy app that uses your phone's GPS - the free app is all I've used, and it worked quite well (aside from issues of simply being able to access the phone), but there are pay options as well.
Speed comes from what you put behind you. - Judi Ketteler