Anybody know what's up with the phone # 1-800-000-0000? I missed this
call recently, tried calling back, and got a recording saying my call
couldn't be completed.

I called my phone company, and they said it might be from a calling
card, or a payphone, but they had never seen it before.

It seems that was either a default number in your carrier's caller ID
system to represent a blocked 800 number or a spoofed number so that
you could not return the call.

One site says to avoid calls from that number as they may be scammers
but the site does not seem to be any source of authority to make that
judgment.

http://www.bizdocuments.com/privacy/identitytheft_tips.html

My 90 year old Grandfather received a call from this number last year.
The lady on the phone told him that his daughters had been in a
horrible accident, on e had died and the other was critical and
getting prepped for surgery. She told him to give her his credit card
number and address so she could send a cab to take him to the
hospital. My Grandfather was understandable upset by this and took him
days to recover from the emotional stress it caused.
If you happen to get a hold of these people I would love to hear about
it. I contacted Verizon, his phone company, and they were unable to
trace the call but said that the number has been reported to be used
by scammers, usually preying on the elderly, I have filed a report
with the phone company as well as the police. Please post if you hear
back from them.

I have been recieving a call once aday for the past 2 weeks..They
call..I answer and they hangup...frustrating!!! How do I block this so
that I no longer recieve these calls?

Tosha

I received 11 calls from this number yesterday...when I tried to dial
the number to find out what it was for, I got a long silence and then
a quick busy signal.  When I see it on caller ID, I just don't answer
it and let voicemail get it (and of course, there is no message). 
This is a very annoying situation.  If anyone has an idea who to
complain to or how to get it to stop, please let me know.

This number is just a default that is sometimes used when the caller
does not have a normal number.  For example, if someone calls you
using Skype, an internet VoIP program, the other persons caller ID
registers it as 1800-000-0000 sometimes.  I've seen it happen with
several other services as well, internet and not.

In short, this number is not a particular person or group of persons,
but a generic default when no information is available.  Think of it
the same as "Unavailable" on your caller ID.