be sure to confirm this boys identity first. send an email to the address they provide and see what they say. do some googling.
something similar to this has done the rounds in australia but it was a hoax. someone made up a story about a boy with leukemia who wanted to break a record by getting cards. they made up a fictional name, address and everything. as far as i can remember it was a school address. the poor school received thousands of letters and still receive them to date. poor buggers spend all day sorting the mail and throwing out the cards.
just found this confirming it is true <a target=_blank class=ftalternatingbarlinklarge href="http://urbanlegends.about.com/library/bl_shane_bernier.htm">http://urbanlegends.about.com/...y/bl_shane_bernier.htm</a> . they make a good point about craig shergold.