Pamela Fox has published a static maps creator that encodes polylines from "My Maps":
http://imagine-it.org/google/staticmap/encodemymap.php
And I improved it:
http://static-maps-generator.appspot.com/
There is this interactive maps creator (API v1)
http://www.solvium.de/static-map/
But the one below also supports polylines (API v2)
http://gmaps-samples.googlecode.com/svn/trunk/simplewizard/makestaticmap.html
