This is a feature request for something that plagues me often when rsyncing from UNIX (Linux and OS X) systems to Windows. NTFS has several invalid characters that are valid under ext3 and HFS+, which often requires time-consuming and tedious renaming operations on the source systems to fix filenames and directory names before rsyncing. In addition, Windows silently strips extraneous whitespace from the beginning and end of file and directory names, but rsync fails when trying to copy files or directories that have this extra whitespace in their names.
There is a very basic implementation of invalid character translation in the "transliterate" branch of the current development rsync: http://gitweb.samba.org/?p=rsync.git;a=commitdiff;h=04dd165c17a8cdc32c74a0e86164c40ab2646ad9