Do you mean send straight away or send without editing?
If working as freelance news/sports photographer, the winner is the person who's photo first hits the picture desk. Snap. Crop. Send.
Photographing a sports tournament or an event where you are selling photos to the general public, there are often runners ferrying memory cards backwards and forwards between photographers. At some events, photos are selected, cropped and sent away to a nearby lab for printing. At others, they are displayed to people at kiosks and printed on demand.
I know some events people who have tried wireless setups for transmitting images from camera to assistants who are selecting and cropping photos, but generally, unless you are shooting at the same place (e.g. karting track, equestrian hall) they're a bit fiddly to setup and a bit too fragile.
As I said, it's horses for courses. Personally I prefer shooting RAW and processing through LR.