> I had to send huge files over a network to another machine.

(That's a bit misleading. SparseFile is about saving disk space
on the server; not about saving bandwidth....)

A quick test on Windows2000/NTFS: Cygwin works as expected,
including the savings. On plain Windows, the full size of the
file is allocated, although the checksums of the files are
correct.

For now, it looks safe to use SparseFile in your
platform-agnostic application. What about OS/X? BSD?

gegroet,
Erik V. - http://www.erikveen.dds.nl/