Ah, don't get me wrong, mate -
I've had some fine swaps with some great folk in Australia, Holland, USA, Finland, Poland, UK, Canada and Trinidad, so I'm not complaining. Far from it. I'm recommending the system and provided it's not misused it's another good tool on a great web site.
I see from Potawi's response that n00bs can be a problem to swap with as we are less careful to avoid cross pollination, and might inadvertently send incorrectly labelled seeds etc, so there are pitfalls, but I've met some great folk and received and sent some fine seeds, so I recommend it.
Hopefully I'll have a good number of seeds to share in February...;-)