I love seeing running photos. What others do gives me some ideas for other things to try. Your photos were interesting since I've never seen a running event in a place like a city.
I think the picture I like the most is Constantina Tomescu-Dita's pic. The way you stopped the arpeture down to bring the shutter speed up to 1/160 is something I haven't seen used by my friends with better cameras much better than mine. They've abused the f2.8 and non-existant depth of field to highlight a runner, so this motion blur and following is a much welcome change to my eyes for running pictures.
I've got pictures of highschool cross country on my website ( http://photos.timaxe.com/crosscountry ) but I haven't really compiled the images into what I consider to be my best since I'm trying to show off everyone and not just 2 or 3 people, so my good pictures are mixed in with pictures of everyone else even if the pics aren't as sweet...all taken with a slow P&S camera
If you want, I could link to the pictures I think stand out from the rest, but feel free to browse through my gallery.