Update, 2nd August 2008
Suddenly it seems that the KML export from My Maps no longer pages like it used to, basically making this script redundant – which was always the intention!
So if your file has under 1000 features, then just use the link ‘View in Google Earth’ to get all the data. If you want the
actual data you can change the ‘output=nl’ to ‘output=kml’ to get the KML data rather than a Network Link to it.
Oh dear, I think I should stay away from the Google Maps Group, following a post (about saving directions to MyMaps) on there a few days ago, realised the KML export is paginated, but there doesnt seem to be a way to get at the following pages directly. It flummoxed me for a while until guessed at the params to get the additional pages, success.
Then a post on there today, made me realise others are coming against this problem, so in traditional hackers** style, here is a little utility to create a multi page network link wrapper…
Export all MyMaps to KML
** follow the link for the definition I mean
Update: 18th Apr, we now download the first page of the map, 1) to get the number of items per page, it seems the link itself is no longer reliable, and 2) it means we can grab the title automatically
(note the download is discarded so I dont keep a copy of the data itself)