Is there a way to check if a particular .Mac username is taken?

Try creating the account?

Try sending an email to whoever it is @mac.com and see if it bounces back.

I did that for the gmail account I wanted to make sure nobody else had taken my username. Basically, it was something along the lines of "I'm just checking to see if someone else is using the username I wanted to get. If you're reading this, then I'll have to think of a different username."

Sadly there isn't a way of doing so without actually creating one.

The way I did it was created an email only account over an existing .mac. This way you don't waste a whole .mac on a name that you might not have favored as much or whatever.

If you don't have a .mac, find a friend you can trust who does and have them check it for you. (I could do this for you, as I have a .mac email only account in addition to my regular .mac name.)

This way, what happens is the person who has the full account will close your account. Then you can take the screen name and make it a full .mac account name, just because you know the account information--which is just the password.

Also a way of checking is by creating an alias. However an alias can not be converted to a full .mac account or even an email only account for that matter.

I'd be willing to help you, if you'd like.

That won't work, as it still might be a recently expired email account. Recently expired email accounts still collect email after a period of time of expiration, probably in hopes you'll renew, even after you had received adequite warning of experiation.

Moreso, though a name might be taken and not be in use .mac does not denote the cause of the bounced emails. So the email will bounce weather or not it might be taken.

The only sure way that I know of, through contacting .mac when I wanted to create an alias as a full email account, is what I had mentioned above.

P.S. Expired names are not available for registration, the only ones who may obtain that address again would be the one who bears the original account information. To confirm, when you go to re-register mbaran2 as a NEW account, for example, as I noted using the method above, it notifies you that the name is unavailable and that you can create a different one or use one they suggest (ie; mbaran3--which would be the next in the series to be available.) The only way to obtain that would be to bring it back as an email only or renew an account.