communication between two people in quick succession (generally, a real time discussion) via IM, text message, e-mail, or some other form of text-only communication.
This term is often used as a contrast to other kinds of communication such as a phone call, skype video conference, or just getting up and walking over to your buddy's dorm room.
Guy: Hey, babe, I've been at my computer all day working on my paper that was due tonight, I really don't feel like slinging text around right now.