Hi everyone, if you are like me and needed to import lots of placemarks into this great plugin then you can using a .csv file formatted correctly and the CSV Importer plugin (which works with custom taxonomies).
Here we go:
1) Download the CSV Importer plugin, install it into your wordpress
2) Create a dummy category (eg: Placemarks) - this is not used but necessary for the importer to work
3) Download the following .csv sample from here file and open using xcel or open office and add your placemark information in the appropriate column: **IMPORTANT** column four (post_type) must have bgmp for every adress, this ensures it is inserted into the Placemarks custom post type, and the plugin will see it.
4) save the file as a .csv using the "save as" command
5) upload the file into the CSV Importer tool in wordpress, selecting your dummy category that you made in step 2.
Unfortunately the addresses do not geo-code when you do this, but all you need to do to geo code them is edit each Placemark once they are uploaded and press "update". It will then geo-code your placemarks.
Also, if you are using Placemark categories, you will have to add these manually as there is no direct relationship between the Placemark and its category. This is due to the wordpress wp_terms_relationships data structure and there is no work-around that I am aware of.