iOS/Web: When you can't get to a web site, you can check if it's down for everyone. If it's a web service like Facebook or an ISP, Downdetector gives you a status report.
This information saves you time waiting on hold, thinking it's something with your computer or Internet connection. If it's a reported outage on Downdetector, there's no point in calling tech support. A big outage might also explain why you have long hold times on tech support.
Downdetector [iTunes App Store]