The US Postal Service is so familiar, so seemingly old school, it’s easy to overlook some of the neat things they do. Things like let customers order Priority Mail boxes online, have them delivered, then pick them up for mailing. More »

The problem with most Amazon filler-finders is their total lack of features. Almost universally they simply list items that meet your price requirements. ClickFiller fleshes out your queries with ratings, rankings, and more. More »

Whenever you spend $25 or more at Amazon.com you become eligible for free basic shipping. Why pay for shipping—usually around $5-10 depending on the size and weight of your order—when you could spend that shipping cost on an actual product and end up with free shipping?

At FillerItemFinder you enter the amount you need to get to $25. FillerItemFinder gives you a massive list of all the items that fit the criteria ordered by rising price.You can filter the results by category and subcategory, narrowing your search to include only "Entertainment" and "Technology" or only the "Books" and "DVD" section of "Entertainment"—the ability to filter by category is what sets this service apart from a filter-less but similar service we reviewed four years ago. Once you've found the perfect filler—Richard Simmons Groovin' with the Silver Foxes, anyone?—add the found item to your cart and you've scored yourself free shipping.

Have a great trick or tool for finding shipping deals online or getting more out of Amazon.com? Let’s hear about it in the comments.

Enter a tracking number into TrackThis and assign it a nickname—like Nick's Naughty Valentine Box 'o Fun—and TrackThis automatically detects if the tracking number is from one of the thirteen carriers it supports. The webapp recognizes track numbers from FedEx, UPS, USPS, and all the way to the freight company CEVA and the international carriers like Canada Post and UK City Link.

Equally as impressive as its roster of carriers is the number of ways it can update you. TrackThis can show updates through its website, or send you updates through email, SMS, RSS, Twitter, or even Facebook messages. So if you really want to see where your mailed item is every step of the way, there’s little chance you’ll be left in the dark. TrackThis is a free service, but does require you to use a Google, OpenID or other compatible service for login. Thanks zyzzva!