Morthor and I have spent some time making a online Map repository
http://aos.minit.nu/maps/
It's still in progress...
But for now you have to mail your maps to me! ([email protected])
Mail a zip or rar file containing
* The map (.vxl)
* Image over the map (in game press M)
* Other images (optional)
* Text file with some info (who created the map etc...)