GMail has introduced a cool labs feature that will help you to search your attached documents and presentations more easily. Termed as Apps search, it essentially extends regular Gmail search with Google Docs and Sites results. Apps Search will find the most relevant Docs and Sites and show them below Gmail search results.
You can enable this cool feature from the Gmail Labs tab under Settings as shown below:
Once you enable it, the “Search Mail” button in Gmail will become “Search Mail and Docs” button as shown under:
You can see that your search results now include matching documents and sites in addition to email messages. You get a suggestion too in case you may have spelled something wrong, just like Google search!
However, mail results show up just as fast as they used to show up before whereas non-mail like the documents, presentations or websites results may take a bit longer. So if you’re just looking for an email, having this lab enabled does not slow you down, instead gives you another cool feature