How do you expess you unapproval?

When you think that your friend acts wrongly, or the decision he/she is about to make appears to be wrong and unacceptable to you, how do you express your position about it to your friend?

What program for communication do you use?

I personally use Skype to interact with my friends, but i know there are other programs like msn, icq, so i'm curious what kind of programs do other people use to communicate?

Alternative ways to bring up the task manager (:

I'm sure that everyone who uses Windows knows about the Ctrl+Alt+Del combo, which brings up the almighty Task Manager, but did you know of other ways to do so, 'cause in my IT class such combination...