Fetcheveryone.com is a very popular website, free and based in the UK. Over 1300 people have recorded a run on the 1st of January, and its all in a league table so you can see how you are doing. If you have a GPS watch you can probably upload the data directly.
As the site owner says 'you can capture everything you do in our training log and spend so long analysing it, you forget to wash.'
Also has good forums, blogs and one of the best lists for finding races.