There are several wonderful Gmail Labs that make life easier. Apps Search is arguably the most useful.
With Apps Search enabled, Gmail Search is extended to include Google Drive and Sites. Need to pull up a particular document and know the name, part of the name, or part of the content? Just use the Search box in Gmail to quickly find it, you don't even have to go to Google Drive!
As Google rolls out the ability to save Gmail attachments directly to Drive, this Lab becomes even more useful. Apps Search is a 'must enable' Lab!
As always, just let us know if you have any questions!