I've added a numerical prefix to all updates so that Google Maps will display your updates in the correct order.
I modified the description to more clearly display the posted date.
The KML now includes <name> and <description> elements that will be displayed by Google Maps and Google Earth. For example, you will now see the following above the list of updates:
Twitter / maxangerTwitter updates from Matt Hanger / maxanger.
I've also verified that you can use GeoTwitter with a Twitter username, not just a Twitter user id. For example, both of the below are equivalent: