In August, Google launched a feature that surfaces your email messages from Gmail on web search results pages when relevant. It has only been available in an opt-in field trial so far, but it seems likely that this will become a regular feature somewhere down the line, or at least be opened up to everybody who wants it.

Now, Google has launched a new expanded version of the field trial, which adds Google Drive files to the mix, so you can see all of your Google Docs and other files appear in search results when relevant, just like the Gmail results. It will also surface Google Calendar content. Google writes on the Inside Search blog:

When you’re looking for something, you should be able to find what you need quickly and easily without needing to think about where it might be, whether it’s in your email or out on the public web. That’s why this past August we opened a field trial allowing you to sign up to get information from Gmail right from the Google search box.

We’ve gotten very positive feedback from those of you testing it out — such as this note: “The Gmail results feature is awesome! The fact that it’s all integrated into one screen is huge.” Many testers have requested being able to find Drive files as well — as one of you put it, “It would be awesome if I could search my google drive from google search as well :)”.

The Google Drive and Calendar content can also be surfaced from a search from Gmail.

To get Drive results, you have to sign up for the new field trial, even if you’re part of the initial Gmail trial. It’s only available in English to users with @gmail.com addresses (not Google Apps accounts).

It seems likely that this will be expanded to Google Apps users at some point, even if Google has so far made no indication that it will. One can only imagine that files and emails available from search can be a whole lot more useful in business and education scenarios.