Since I sometimes sound like a robot when I answer the phone, I often think about the right way to answer the phone.  At home, it's pretty simple:  "Hello?"  I don't have caller ID, and I don't want to give out any personal information because the idiots that call my home phone are usually trying to sell me something (except you, Wendy's mom [and you're not an idiot]), so I stick with something plain and simple.  My cell phone has caller ID, and of the two or three calls I receive each month, I always know the caller, so I greet them by name. 

That leaves my work phone.  Many of the people I work with have a habit of using an official greeting.  They pick up the phone and simply state the group we work in.  No "Hi."  No "This is [X]."  It's like the Cosby Show:  "Huxtable residence."  But we have caller ID at work, and these same people use the same greeting for everyone, which is stupid, especially if the caller doesn't work where we work.  It was especially annoying with a guy who used to work near me.  He would get a few hundred phone calls every day, and every single one of them was a personal call.  But he would still do his stupid official greeting every time.  I always thought, "You barely work for our group, so you probably shouldn't be using our name to represent yourself." 

Update (2008-03-21 2:32pm):  This post is lacking.  Here are a few examples of good phone greetings: 
  1. Tom Miller (from KRHS):  "Whooo is it?"
  2. Kramer (from Seinfeld):  "Go."
  3. "Talk to me."
That is all. #technology