CTAN has a new package: refreshpdf
Refreshpdf is an Applescript that takes the path of a pdf file as argument and then opens the file in Acrobat. If the file is already open in Acrobat, then Acrobat is told to close and reopen the file and to go to the same page that was displayed in the closed file. The Applescript can also be called from the command line by a shell script "refreshpdf". Refreshpdf only works on MacOS X.
This package is located at http://tug.ctan.org/tex-archive/support/refreshpdf . More information is at http://tug.ctan.org/cgi-bin/ctanPackageInformation.py?id=refreshpdf (if the package is new it may take a day for that information to appear). We are supported by the TeX Users Group http://www.tug.org . Please join a users group; see http://www.tug.org/usergroups.html .
refreshpdf – Refresh PDF files "remotely"
Refreshpdf is an applescript that will ensure the current copy of a PDF file is open in Acrobat reader; this may require that it instructs reader to close and re-open the file.
Users of non-Macintosh X11-based systems may use the commands from the xpdfopen package.