Why no UPS? According to the updates on Simple Tracking, it seems UPS is particularly stingy in allowing access to their API, despite their competitors openness. For most other delivery services, though, Simple Tracking is streamlined. It recognizes the different tracking numbers you paste in automatically and returns results immediately. You can then subscribe to the feed for that specific tracking number to see updates on the status of your package in your favorite RSS reader. You don't even have to copy and paste from emails or shopping sites—there's a Firefox extension that adds a Track XYZ Package context when tracking numbers are right-clicked upon. There's also a phone-friendly version of the site available for on-the-go checking. If you prefer email-based updates, check out previously reviewed Track My Shipments for stop-by-stop updates. Simple Tracking is free, requires no registration for use.