Oh well, here it is if anyone wants it.. I've repackaged it up a bit and stripped out anything that wasn't need to just do synchronisation.http://www.newdawnsoftware.com/resources/pxsync/pxsync.zip
Contains source (Java and C) and binaries.
To wait for vertical retrace do:
VideoSync exists in the "de.pxlab.pxl" package. Full credit to the pxlab authors who I haven't heard from yet. However, since its "Free Source" there shouldn't be any problem.
I've added it as an optional thing to Mini Adventure (i.e. you can turn it on in the options). Seems to work fine. Mini Adventure is webstartable if anyone would like to try it out. (http://www.newdawnsoftware.com/miniad