Please id this
It's not a leech, but a slug. It likely came out because of all the wet weather. I am not sure what type, but many slugs can be destructive garden pests.
Here is a Fact Sheet on slugs from CSU Extension: http://www.ext.colostate.edu/pubs/insect/05515.html
Thanks. Not as interesting (to me anyway), but a relief just the same.