Google results showing address on map?

I have come across this recently where when I search for something like "software development" in google the result is usually a list of companies, this then shows the results as per usual and adds a google map to the right with (almost) each result as a marker on that map.

Is there a way for me to force google to do this to my site or to at least make it more inclined to do it for mine (maybe by adding an <address> tag), or is this just one of those where it either happens or it doesn't.

I have not seen this before. I tried typing software development like you said, but am unable to duplicate this. I am not seeing any locations on maps for any of the businesses. When you get a chance would it be possible for you to post a screenshot of what you are seeing? I would be curious to know when these sort of results show up, and what can be done to optimize your website for it.

In order for the map to show you need to search for "keyword" in "city". [for example].

As far as to how to get on the map... Read here

All right, I have figured this out ... The thing I was looking for is Google Places. What happens is I add my company to google places and in the process I add my url, then when google returns my url in a result it adds a map because it sees that I am on google places and places a marker on the map.

Example:

I had been noticing that on a lot of my search results lately. Nice to know what triggers it.

They updated their site search from the black menu bar to site links then combining both local and global searches and now including the map and address for each business.