QR Codes

"A QR code (abbreviated from Quick Response code) is a specific matrix barcode (or two-dimensional code) that is readable by dedicated QR barcode readers, camera telephones, and to a less common extent, computers with webcams. The code consists of black modules arranged in a square pattern on a white background. The information encoded may be text, URL, or other data."

This is a great way of quickly seeing something, not having to worry about writing it down or panicking - you simply take a picture with your phone and it will direct you to the website.