The act of keeping your Skype window open and watching to see if a particular person/persons are logging on to Skype, while keeping your status as "available," then changing it to an unavailable or away status as soon as you determine that they are probably not going to initiate contact. This is done to essentially see whether or not a contact on Skype is genuinely interested in speaking with you, or to determine how much time they spend on Skype not speaking to you.
I cannot believe that he logged on a half hour ago and has not even sent me a message! I am going to keep my status as "Online" and do a Skype Showdown to see if he will initiate contact before he logs off. He must be talking to another girl.