If you use Gmail, you probably know that Google can parse your email receipts for things like package tracking in Google Now. If you want to see a list of your most recent receipts — or see one in particular — you can just search "my purchases" on Google.
Searching "my purchases" brings up a list of your recent receipts, with a dropdown to show 10 more. You can also search for a specific item to bring up a specific receipt, like so:
Obviously, you've always been able to do this in Gmail, but this is a bit quicker. Not only does it save you a click or two, but you can do it right from Chrome's address bar, since it's a Google search. Pretty handy.
Find Your Purchases Using Google [Google Operating System]