Well this is cool! more Inter-Integration of Google+ into other Google properties, this time via the BlackBar *.
This was a simple button (Share...) that looked like an afterthought, just next to the orange notification count on the top-left of the screen, but it's turning out to be something huge! Now, when you go to Google maps and click on the Share... button it adds some context with it into the sharing widget (instead of just an empty Text input area).
Obviously this exists on Google.com only (where the bar has been added), but I can see it growing into a widget you can embed on your own website - an HTML5 replacement for the Extension/Add-on toolbar we have grown to love/hate...
This integrates with the +snippets announced earlier ** capability which allows you to embed special snippets in a map (and in any website) and have the share button automagically detect them and have that data pulsed/beamed directly to the users' Google+ chosen circles when he clicks the "Share".
This also ties directly into the +1 button which is a different beast, but very similar in effect for regular non-google websites. The +1 Button this button has been significantly upgraded in the last two weeks *.
Wow, this is growing fast! This is just the tip of the iceberg in terms of what Google+ is capable of (and will do, in the future)!
* I believe the black toolbar is going to turn into a full fledged HTML5 Google Toolbar eventually, which users will be able to add as a Chrome extension, and website owners to embed in their websites for integrated site-search capabilities etc... Huge, if this happens - I thought of this first! ( )
Ref: Post on Google+: https://plus.google.com/102370937568758228574/posts/JTmpDDy9RAy