How to use maps in an app with unlimied domains?

I have an app that's used on many websites and different domains. Not a low amount like 5-10, more like 200+

And I want to display something like a google map.

Their API key has to be manually requested each time. -We have to avoid this.

Is "Using a Bing Maps Key to access the Bing Maps SOAP Services" a solution?

Or is better to create a single web page on a separate website that displa开发者_运维技巧ys any map. It would get the map pin point from a query string. Then display this map using an iFrame.

Looks like eventbrite does that: http://www.eventbrite.com/googlemap?eid=1885257857&iframe=Y

Bing Maps requires a key per domain, so thats not an easy thing to achieve. You have two options as I see it:

1) Create one map on one domain and share it with all the other sites using and iframe 2) use google maps v3 as that no longer requires api keys and is therefore not locked to a domain