Its exactly the same as sockets on a normal operating system (well, mostly the same), so the difficulty is around the same.
Otherwise, you could use the dashboard class in conjunction with the labview dashboard viewer to send data that way.
Something we've been doing is just writing data files to the cRio filesystem and retrieving the file via FTP. You have to call Priv_SetWriteFileAllowed(1) or something to that effect for it to allow you to write to the filesystem however.