We had a good thread on this not that long ago that would be a good read.

In situations that are not yet TEOTWAWKI, the concept of a "time bank" apparently is catching on in Greece as many people just don't have the Euros to pay for a lot of things. In a time bank, you trade time/services, like an hour of babysitting for an hour of piano lessons. So you don't necessarily need specialized skills like a doctor or mechanic to barter your services.

Personally, I don't think barter would ever be the main means of exchange, or not for long. It's just too unwieldy for frequent day-to-day needs and if trading a lot of consumables, the supply of them are going to be used up fairly rapidly.

And with large or expensive items, it's going to be hard to weigh relative value. People will get ripped off a lot with big items, probably because one side doesn't have a choice and are desperate.

If things really got that bad, I think some sort of alternative currency or scrip system would come about, or perhaps certain items, like cigarettes, would essentially become money. You wouldn't trade cigarettes so you could smoke, you'd hold onto them and trade them for other things.

Unfortunately, I think it's hard to predict what items might become some new trading medium. Bar soap? Sewing needles? If cigarettes, maybe only a particular brand will be acceptable as money and anything else will only be good for smoking. I was reading about a recent example of cigarettes as money a while back, but I forget the details or where I read it (did I read it on ETS?). Only one particular brand was acceptable, though, like Merit or something like that. If you had a closet full of Camels, you were out of luck. You could still trade, of course, but you'd need to spend more effort to negotiate a trade.