I have found various articles in the knowledge base, reference guide and on alt-team docs about adding a store locator page, but everything is grossly outdated.
Google has developed their APIs much further and the referenced Google MAPS Javascript API v2 is deprecated.
Which API should be used?
It seems that the current Google Maps Javascript API v3 does not work with CS-Cart.
The documentation states that there should be a 'store locator' menu item under 'content' in admin panel.
This does not exist. But I did find something under administration.
I have multiple brick & mortar stores that I want to add per storefront. How do I do this? I only see the possibility to add stores for all storefronts.
Is there any way to add Google Places, Facebook business, Foursquare to the store locator page?
Store Locator is found under Addons. I haven't yet tried to use it in Ultimate for more than 1 store location though.
Yes, you can activate it under addons and add a API key.
Under administration > store locator it is possible to add stores.
Its possible to add long/latitude coordinates, which is far from exact.
However, Google then gives the following warning:
[quote]Google has disabled use of the Maps API for this application. The provided key is not a valid Google API Key, or it is not authorized for the Google Maps Javascript API v2 on this site. If you are the owner of this application, you can learn about obtaining a valid key here: Google Maps Platform Documentation | Maps JavaScript API | Google Developers
But on the page that Google links to, this warning is listed:
[quote][color=#ff0000]Note: The Google Maps JavaScript API Version 2 has been officially deprecated as of May 19, 2010. The V2 API will continue to work until May 19, 2013. We encourage you to [/color][color=#ff0000]migrate your code[/color][color=#ff0000] to [/color][color=#ff0000]version 3[/color][color=#ff0000] of the Maps JavaScript API.[/color][/quote]
It seems to me that this function no longer works in CS-Cart. Unless I am missing something.
It's still working here… but working or not working, the store locator is pretty crappy. Most annoying thing:
You add a shop, The content gets created in all languages. Now you'd like to edit the address. You have to do this for every language.
So make sure to add the address correctly in 1 go.
Also annoying: you have to find the coordinates for every store yourself.
Yes, it still works if you already have an API key. But you cant get a new API key. And your API key will stop working in 2 months.
Ah, well I will have moved this site over to another cms by then (we are changing it from a shop to a brand / info site), so good timing 
Are you using Wordpress for your store locator?