A picture you take of yourself to verify your identity on the Internet. To make a salute, you take a picture of yourself holding up a sign of some sort that says your user name or e-mail address, depending on the sort of site it is. For instance, on LiveJournal your sign would say your user name, and for MySpace your sign would say your e-mail address. The salute is more or less only used for sites where you post pictures of yourself and is in existence due to the fact that there are so many people who steal other peoples' photos and claim to be that person, and when you have another picture of yourself being the person that is in the photos clearly holding up a sign saying the user name you are under, it is indisputable that you are the person in the photos you have posted.
"In order to verify your identity, please send us a "salute". This means we will need an image of yourself holding a handwritten sign with the word "MySpace.com" and your Friend ID (your Friend ID number appears immediately after "friendID=" in the web address/URL when viewing your profile). We can then remove the profile that uses your identity without your permission."