Ok, to access the server manager from the web on 5.5 and 5.6b1 goto
server manager
Remote access
At the bottom of the page is
It is possible to allow hosts on remote networks to access the SME server manager by entering those networks here. Use a subnet mask of 255.255.255.255 to limit the access to the specified host.
Click here to add a new entry.
Click on the hyperlink 'here'. It will take you to a page where you can set up an ip address and subnet mask to allow SSL (https://) access to the server manager.
If you want access the server manager from anywhere on the net use ip 0.0.0.0 subnet 0.0.0.0
save then save again
Of course it is a bit of a security risk but if you have an admin/root password that is as long and as difficult as you can remember then I feel that the risk minimal, but you do do this at your own risk.
Jon