i like to ignore people when i'm out unless they talk and approach me
but really, when so many people instantly aggro or shoot you (ahem ranma:P) its kind of difficult to find the urge to stop for friendly chatter.
Although i do stop when i see newbs building somewhere close by, if they need help or whatever, but if im jsut wandeirng in a boat and see someone else in a boat, then likely chances i'll go in a different direction or port.