Thought I would post another notion for a scifi larp now that I am not deathly ill.
Real world has some tech toys in it that people will want to bring. Laptops, pda's, video camera's. People will want to have access to the technology they can get. I think this is fine in a sci fi larp as long as there is some mechanism to prevent abuse. So that being said there should be no device with some sort of effect that does not have a tag to keep track of it. I.e. if you want your charicter to carry around that real tricoder you bought on ebay fine. Just show it to the guys running the game before you bring it inplay so we know it is there and it has a tag. The other coralary to this is if your charicter is going to have a lot of cool gadgets then you best take an increased wealth advantage to afford the in play costs.