First of all, when dealing with lightning, there are no sure-fire ways to protect things. All you can do is try to minimize chances of a direct hit and many of our feeble efforts may or may not work but having said all that, here's what I've done:

First pic is a grounded mast with a stainless wire brush that consists of a lot of sharp points. The thought being that a sharp point will tend to let any charge bleed off better than it would from a round ball that will tend to accumulate a charge before it lets go in a larger spark.

Second pic is the 900 MHz antenna mounted on a standoff arm that's at least 1 wavelength away from the mast. Seperation from the mast tends to keep antenna radiation symettrical and not have a shadow caused by the mast which would keep radios in the shadow from seeing the radiation. Having the antenna below the high point of the mast should lessen the chances of the antenna suffering a direct hit.

Third pic is the antenna and mast up in the air..

Fourth pic is a gas tube discharge device that can bleed off charges before they travel down the coax and into your device. This device contains a replaceable element that should be changed in the event it sacrifices itself when absorbing a static discharge. Also notice the coax coming from the antenna and leading to the gas discharge device -- I've formed it into a couple rather large coils. Sometimes a lightning bolt can blow out one side of the coiled coax because it doesn't want to go round and round the coil and in so doing bleed the majority of the jolt to ground via the shortcut it's made.

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(antenna.jpg)

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dissapator.jpg (64KB - 126 downloads)

antenna.jpg (44KB - 123 downloads)

1up.jpg (90KB - 139 downloads)

11loop.jpg (171KB - 112 downloads)