Roy from morethantechnical has some a pretty cool hack with his samsung vibrant and a pico projector. I’ll summarize his hardwork here but you can take a full look at their website.
On his phone he made sure that tv out was enabled.
He then prepared a 3.5 mm 4 pole connectors
He then said “so on the other side of your custom cable, you may use a mono 3.5mm 2-connector plug because that is all you need, but if you bought bulk 3.5 4-connector you might as well use that. Now you should mind that you need the sleeve to get the signal, so connect Vibrant’s Green to MPro110′s Green, Yellow and Black. MPro110′s Red, the tip, should go to GND.”
Nice little hack. More work than most people are up to doing but this just shows how you can do your own hack instead of buying the branded cable instead of a generic one.