Wow. Little did I know that synchronization (I discussed a sync product a couple of weeks ago) was such a big deal. I've been flooded with responses and have sent out more than 100 invites to the Dropbox file synchronization service I reviewed. If you requested an invite but haven't seen a response yet, send a message to gearhead@gibbs.com with the subject "dropbox" (if you sent me a message without that as the subject I may have missed it). 

Reader Craig Anderson (Tampa, Fla.) asked if I had ever used or reviewed the free, open source software synchronization package called rsync (Yes and yes).

Craig said his organization has used rsync for years as the basis of its disk-to-disk-to-tape backup system: "We have several small remote offices with local Windows servers that we mirror to HQ (to a whitebox running Linux with SATA-RAID) using rsync, and then backup the mirrors to tape." Nice solution Craig, and it has the advantage that you own and control the entire thing. That said, it also has the disadvantage that you own and control the entire solution.

Craig continued: "rsync can run as a command-line or as a *nix daemon or as a Windows service in both directions. That's right, the service can run as a source or destination on a per 'share' basis. It can even run inside of SSH."

If you haven't checked out rsync you should first peruse its Wikipedia entry and then visit its Web site. Rsync is a very active project, and the latest version, rsync version 3.0.4pre2, was just released, on Aug. 2.

For Windows there's a very good port called cwRsync, as well as ports for Red Hat and Fedora, i386 Linux, and Sparc/Solaris and X86/Solaris.

For Mac OS X port there's a sophisticated port called RsyncX with wizard-style "assistants" for performing various client- and server-orientated operations, drag and drop support, and the ability to create a bootable copy of an OS9 or OS X system. There's also a very useful primer on RsyncX called "HOWTO Backup Your Mac With rsync."

The RsyncX site provides a variant called RsyncXCD. This utility is based on the latest release of bootCD, which "will let you connect to your server as a Mac OS X client, and cleanly install your image folder onto a volume that later you will boot from."

In response to my question about what people are using for synchronization, reader Jim Addlesberger said of FolderShare: "The product is easy to use and reliable. I sync important customer and vendor files, as well as my QuickBooks, between my desktop and laptop using FolderShare. I use ACT as my customer database (some 20,000 contacts) and I use the internal ACT sync to keep that up to date."