QR Codes strange looking symbols

I've noticed these strange looking little symbols all over the place lately, but until recently, I didn't know much about them.  They are called QR(quick response) codes, and have been described as "bar codes on steroids".  

Originally developed by a Japanese company to track automotive parts, these little designs can store up to 4296 alphanumeric or 7089 numeric characters depending on the level of error correction applied(not sure what that means).