How about having a shield you can put into a small or large weapons port. It gives you 1000 additional hull for the small port, and 2000 for the large. Very nice way to defend against rocket ramming and probably traders would prefer more hull over offensive weapons.

I've got a different but similar idea regarding trading weapon slots for better defences. You can read a detailed explanation here:

http://vendetta.guildsoftware.com/?action=msgboard&thread=1416

Note that I want both 'armor' and 'shields', but I would prefer that shields were implemented using the same system as the armor - ei shields reduce the ammount of damage you take when you are hit by a weapon - only with 'shields' rather than spending an 'armor slot' or a weapons slot, you would spend one of your limited 'equipment slots' and a certain ammount of power continiously (perhaps with a slider to pour extra power into shields) to gain more 'armor'.

I really would rather avoid having Wing Commander/XvT/Descent Freespace style shields with a 'rechargeable armor battery'. Its a standard of these style games, but I don't think it adds all that much to the gameplay. Afterall, we already have one rechargable 'battery', the well 'battery', and having another is just strategically redundant. However, it would be good if we could decide whether to spend that energy on defence or offence, and so I do promote a shield system to 'buy' armor with energy.

It's good to see someone else offering a shields idea that isn't just a rehash of some other games gameplay.

Of course, some people really like the 'rechargeable armor battery' and it has the advantage of being familiar to everyone.