Sometimes an acronym is used for so long that people consider it a solid word, and forget that each letter stands for something else. Common examples are laser (Light Amplification through Stimulated Emission of Radiation), radar (RAdio Detecting And Ranging), and sonar (SOund NAvigation and Ranging). But what of unpronouncable acronyms, those that must be spoken as their individual letters? All too often, one of these acronyms will be used, and followed by the last word in the acronym spoken outright. Examples of these redundancies include:

"ATM machine" (Automated Teller Machine machine)
"RAM memory chip" (Random Access Memory memory chip)

Can anyone think of any others?

[P.]

Oh, I hate that! The one that irritates me the most, since I hear it so often, is "pin number". This could be said "pi number", but that means something completely different (-: I can't think of any others at the moment except "HTML language" and "ASP page".

Another one is scuba (self-contained underwater breathing apparatus).

Pin number irks me, too. There's also the college entrance exam, the Scholastic Aptitude Test test.... and (showing my age) the post-Cold War negotiations, the Strategic Arms Limitation Talks talks.

How about a Compact Disk disk or a Digital Video Disk disk? Then there is the Personal Computer computer.

On applications for credit cards, etc., I often see the following asking for my Social Security Number:

SSN #________________

Does that one count? Nothing will ever be as irritating as "PIN number," which several have already pointed out.