I once made the comment that Sayyid and a few Losties should raid the abandoned camp to gain materials needed to cobble together a simple radio. It just occured to me, Hurley's VW has everything Sayyid would need to make a simple morse code transmitter/receiver with antenna (wire).
At the right time of day/night, atmospheric conditions allow for insane distances of transmission/reception of simple radio signals, there are hobbyist called 'DXers' that get into this stuff. Sayyid would know about this stuff and would easily be capable of putting it together.
The van would have wire (speaker/lights, etc) for antenna, the radio would give the basics needed for signal generation and amplification, alternator + voltage regulator would give basic electricity when coupled with a little 'windmill' to crank it.
Toughest part would be basic tools, but with enough time I'm sure Sayyid could pull it off.