Answer: By Post is the simple answer.

If you know them via school or work you can do it there I suppose, but not outside school, and if you are a kid and slightly unsure ask your parents or guardian first.

I strongly suggest that you do not meet up with people you meet on any site unless you are 7ft tall and are an expert in unarmed combat and have a bullet proof vest. : )

Seriously NEVER meet up with somebody you meet on line.

I will just type that again: NEVER EVER  meet up with somebody you meet on line

I am thinking of adding a middle man service where both people send their swaps to me and I then send them on. There would be a charge for this.

If there are enough people prepared to pay £3 each for this I might do it.

Advantages: Your postal addresses stay private. You never send off and get nothing in return.

Disadvantages: It costs. It takes longer.