I pay by plastic all the time. I also use Paypal a lot with no discernible problems. The one thing that will not do nicely is American Express and Diners Club. Their charges are extortionate and you wll find that many UK retailers will tell you their system is down!! I have sent wll concelaed cahs with no problems and if the worst comes to the worst I (like has been indicated find posting travellers checks as good as anything) but just as risky as cash of course.

Dave
www.collectorsfolk.co.uk