like i went to install a wireless nic on my laptop and i didnt have the driver cd for it, just the files on another computer, 15 minutes of serial transfer time and i got the drivers copied and installed, then i enjoyed my usual bandwidth and put the serial cable in the back of the closet.
ive seen an option of using a parallel port instead of a serial port and supposidly it gives you transfers 8x better than serial. the net drivers for dcc connections in newer windows versions as 'direct cable connection'. i think you can git em up above 1 mbit. be sure to set maximum baud rate in the device manager panes.