Amazon’s delivery lockers have been sprouting up everywhere since they first arrived in late last year, appearing in several cities in the US and UK. The world’s largest retailer’s newest partner is Staples, whose office supply stores are the latest to house the lockers, reports Reuters. Amazon Lockers function as single-use post office boxes, allowing online shoppers to pick up their packages at a time that’s convenient for them, without having to schedule deliveries. Amazon has already partnered with a number of brick-and-mortar stores in the US and UK to house the lockers, including 7-Eleven, Rite-Aid, Safeway, and Walgreen’s. We're sure that whatever Amazon is paying makes the deal worthwhile for Staples, but having such a close competitor effectively setting up shop in your stores has to make the relationship a little awkward.

Update: By searching for Amazon Lockers around San Francisco and surrounding cities, Geekwire has discovered that RadioShack will also be taking part in this new program. The site also searched and found some Amazon Lockers in grocery chain Albertsons in southern California. While this hasn't been officially announced, it looks like Amazon has at least a few retails partners on board.