We have seen this all among arabs. Nose to nose greetings, cheek to cheek and sometimes they kiss/smack for slight seconds of each other's lips after saying salam alaikom. And they're repeating it so many times, twice or thrice at left cheek and same with the right cheek (im counting it though) so with the nose to nose greetings.
Since i am not an arab i would like to be enlightened by their act of greetings. They said that "arab greetings" differ from the level of their relations to each other. If you're just a friend it is "cheek to cheek" and nose to nose for blood relations.
I am not sure how true these things are and so i would like to know from forumers. If this has been tackled here before then i would love to see the link (though i did some search can't find any).