I think my worst drink and dial was when I phoned up an ex I hadnt seen for 5 years and confessed my undying love to him. Then my phone ran out of battery, so I simply grabbed my current boyfriend's phone and rang him back on that. i was so paranoid the next day that my current boyfriend would get a text from my ex thinking it was my phone!
Also went through a phase of ringing random numbers on my contact list and singing "Its a long way to tipperary" to them. They thought it was funny to begin with, but think the novelty wore off after a few times
Maybe pass on the radio one flirt divert number, so we can all have a good laugh at a druken song, esp as by that time of the day im pretty fed up (I think it may be the fact that radio one plays the same four songs over and over again!)