Guess Who?

There are different kinds of annoying people. People who say "En experience un vayasu". People who say "My tamil is not all that good but somehow I used to get good marks at school" and you know both parts of the statement aren't true. Celebrities who say "Da Vinci Code naan romba 'like panni' padicchen". But the ones at the top of my list right now are the ones that call you and say "Guess Who?" You might say the ones that take a wrong guess and continue the conversation for the next half hour without knowing the caller's identity are also annoying. But I categorise them under "stupid" category. The sample conversation could be like this when you are actually in a meeting at your workplace.
Your phone rings. By mistake you press the answer button instead of the silence button on your phone.
U - Hello
X - Hi
U - Hi..?
X - Guess Who this is?
You want to be civil in front of your collegues, so you say
U - I don't know.
X - You don't know me? You can't recognize MY voice?!
U - Can I call you back? I am in a meeting. (You really wish you could use the choicest of swear words but you restrain because your collegues are now following your conversation)
X - You are working! Since when? So is the meeting more important than me?
At this point you want to send a bomb through the phone.
U - I am busy, I have to go now. Call me later.
You cut the line only to be called again and this continues. The best way to take revenge is doing this to someone else.;-)
As a caveat I gotta add that I've been a little stupid and also a little annoying myself but not anymore.