For those of you who don't want to bother with IRCs, etc., it's possible to buy your printable stamps for SASE directly from the foreign (or national) post office and print it in the comfort of your home printer ...
SASE for USA:
https://sss-web.usps.com/cns/landing.do
SASE for UK:
http://www.royalmail.com/portal/rm/j...iaId=106700775
SASE for Canada:
http://www.canadapost.ca/personal/tools/cst/intro-e.asp
SASE for Australia: a bureaucratic system of forms that'll most likely not work unless you live there. (But feel free, anyone, to prove me wrong.)
Cheers,
...Alex