Spacebar + grab (on PC) pressed at the right time lets you skip most of the dialogues in the game. 100% possible on PS2 (Arsene1412 used this in his run) and probably on XBOX, too. Some skips require unique setups, while others are straightforward. The following dialogues can be skipped during the run using this method:

• with Luca during The Alley

• with Galtosino during The Enforcer (approach from the side and perform a quick fling - check any% WR for reference)

• with Tom before Enforcer promotion at the Corleone Compound

• with Clemenza before Intensive Care

• with Frankie during Intensive Care

• with Clemenza before Fireworks

• with Clemenza during Death to the Traitor

• with Monk at Corcoran's Perch before Horseplay

• with Tom before Horseplay (approach from behind - check any% WR for reference)

• with Tom at the Chateau Leive hotel in Midtown (approach from the side - check any% WR for reference)

• with Sonny before and during Sonny's War - one at the Compound, the other at Lucy's place

• with toolbooth attendant during Change of Plans

• with Tom and Willie before It's Only Business

• with Clemenza, Willie and Neri during Baptism by Fire

Saves quite a bit of time and is highly recommended to master to get good times

maybe this could work with PS3 though it might not be different from the one I use to skip by mashing Start.

discovered two more:

• with tom before "Intensive Care" • with tom before "A Recipe for Revenge"