Has anyone flown as a courier on courier flights and how good are they?

I have done a little research on them and they all seem to require you to become a member and pay an X amount of money for the pleasure.

Thanks.

I looked into courier flights a few years back. Most of the companies I contacted required some payment for the flights, and the savings compared to "normal" cheap air tickets were not spectacular.
But, if you happen to live very close to a major international airport such as Heathrow or JFK, it might be worth your while phoning round all your local courier companies (if you haven't done so already) to check on the current situation.
Good luck!
Pete