What would I barter? Pretty much anything I have that I think is worth losing in order to gain something else I need.

As a specific item, I like bartering in alcohol. I figure it's not really essential to my survival and if they're totally inebriated they're less likely to be a real threat.

With that said, I will not barter weapons/ammunition. I know some people who think .22lr ammo is a great bartering item, but I just feel like there is too much potential for it to be used against you. Plus I'd rather not let people know whether or not I'm armed unless I have to; as it could make some situations more tense than they need to be.