I always felt that someone should do this for E-bay:
Step 1) Buy some bloody big wharehouses, in my case, scattered across the US.
Step 2) set up a website, internet stuff, and hook up with e-bay so they'll have a button to use your services
Step 3) the long one- every time a pair of people use your service, you give them an identification number, they tell you what the product is, and how much it's going for, they send you the product with the final destination labeled inside, and the ident. number outside. You take your cut of the money (this would happen thru pay-pal or check inside the package again) Now that you have both products, or money, whatever, you send both to the respective recipients. Voila instant safety. It'd even work with houses and stuff, by holding the deed.
If you want to be really fancy, you could even try to test products to see if they work (for extra $$$ of course)
