Mapping thru SSL, Secure connections (HTTPS) and "premier" connections

Google Maps API Premier customers can access Google Maps API HTTP services over a secure connection.

I plan to set up a new mapping site and I'm curious how far I need to go to secure it.

What I would like to do is plan for it in a manner to allow for future SSL compatibility without having to get into the overhead costs of Premier services for secure connections ... which I think means I need to stay away from those modules which play nice with mapping services which offer "free" only up to a certain level...

Does anyone have experience with the best way to 'lock down' a mapping site in an open source kind of way?