Ass Dialing 

"Ass Dialing" is something usually achieved by people with very large, very talented asses who wear cell phones on belt clips. When they sit on their phones, random button presses result in random calls all over the world. The recipient of these calls hears nothing but a stream of DTMF button tones and muffled conversation.

My brother ass dialed me last night at 2am. I think he was at a party.

Ass Dialing by Kevin Kelm January 28, 2003

ass-dialling 

the ability of an unlocked iPhone to dial it's address book randomly when activated by pressure in your rear pocket.

'Dude, you called me, like, three times last night...'.

'Yeah, sorry man, my iPhone was ass-dialling'.

ass-dialling by P-Dew May 24, 2009