Running under Windows, I have no need for a "shebang" line. Windows associates a file to its type via the file name's extension or a constant signature at some fixed offset in the file, and does not hard-code the location of the executable in the file. Until reciently the Mac has stored a file type as meta-data which is not in the file's text, so those users have to set the type themselves after downloading, anyway. VMS is totally different, and (according to perlrun) uses a couple lines at the top of the file that would not run on other systems (since it doesn't look like a Perl comment).
So, it looks like Unix systems are the only kind I can really address in regards to making my script friendly across systems. I can put a shebang (why isn't that shAbang, if it's short for sharp-bang?) line at the top of the script that I publish.
So the question is, what should it say? Different people install Perl in different places! Perlrun encourages two "standard" locations to be symlinks to the actual binary, and I suppose something like that is common on Unix systems. Is one better than the other? What do people really like to use these days? It also mentions the use of the env program which adds a level of indirection (sounds like a good idea) but mentions that not everyone has that.
So, what's the "best practice" for setting up the shebang line?