Need help creating a Google map route

I need the function for my users to add a route that can be seen in a google map. I’m having trouble figuring this out.
Here’s the details on stackoverflow
http://stackoverflow.com/questions/17893529/how-do-you-make-a-a-b-route-in-a-google-maps-widget

Also I’m wondering if there’s any plugin able to take a ‘snaphot’ of the google map and make an image out of it that would then be set as the post thumbnail?

Thanks in advance guys!