I’ve run the half-marathon
Last Sunday I participated in Warsaw’s half-marathon. I’ve run it to the end, 21km, in just under 2 hours and 5 minutes; that is an average speed of ~10.1km/h. I was lucky the weather was good, warm and sunny.
All in all, it was a great experience, and I’m really happy I participated. I would recommend it to anyone to run a half-marathon, at least once. And it’s not that hard: I’ve only had 2 weeks of training (running in the park) prior to the course. For two days afther the half-marathon, my legs muscles were hurting a bit..
My wife waited for me at the finish line. We were expecting I’d take 2h30min, and she was surprised by my performance 
I’ve got a medal (everybody who finished got one), and there will also be a nominal dyploma mentioning my time.
And a tip for prospective long course runners: you may run as slow as you want, as long as you keep running (not stopping or walking). If you get tired, or you can’t breath enough, slow down the pace as much as you need, but keep running — this is the most efficient way to gain time (not stopping).