> The equivalent in PC terms, to turn it around, would be if a PC user sent
>you a Zipped file; you wouldn't be able to read it on the Mac.

Just to whom it may concern - ZIP files may be read/written with a Macintosh
(I use this format to transfer files bigger than 1,4 Mb from the Mac to PC
and vice-versa).

There are two applications which you must have to do this on the Mac. One is
Stuffit DeLuxe (with Expander Enhancer). It allows you to read and write in
ZIP format.
The other (and my favorite) is ZipIt. Any one of them does the job
perfectly, but I had some problems with Stuffit and spanned files (never had
any with ZipIt).