I received a call from this number but my cell was off.  No message left.  I am happy I did not answer because it would take up my minutes!  Stupid unknown critters!

this number has called me twice now.  in a span of 5mins.  no message.

I just got a call from this number today.  I didn't answer and they didn't leave a message.  Probably was "selected for more free airmiles"  :P

this number has called me twice now.  in a span of 5mins.  
no message.

Got the call X2 today.  Did not answer and they did not leave a message....assuming it was an offer I just could refuse to answer.