Anyone recommend a good battlemat/virtual tabletop program

By lurkeroutthere, in Rogue Trader

So we're getting down into our first ship to ship combat soon and given that their current mission is one of pirate hunting the group may be at it for a while. We've futzed around with battlemats a bit but more and more interested in some kind of computer program i can output display to a screen and show movement and positions there. It doesn't need to do any of the automation, just show pcitures of ships, objects of interest and other items. Anyone have any recommendations? Google foo recommends several but i thought i'd get actual people's feedback.