I need to be able to do a periodic sync of content off my Windows 7 x64 laptop to my offsite CentOS 6 webserver.
Is there a tool/mode like rysnc for WinSCP or similar?
For a variety or reasons, Dropbox is not an option here.
Use Synchronize (Ctrl-S):

The prompts afterwards walk you through what you need to do.
There is cwRsync which I use for backing up data from Windows PCs to Linux servers.
Older versions are available without fee
As per @warren's answer, WinSCP can synchronize files.
If you want to do it periodically, you need to script it (WinSCP supports scripting) and schedule the WinSCP script using the Windows Scheduler.
The Sync-Option didn't fit my needs. cwRsync also didn't work for me, gave me an Error on Win7 x64.
I used cygwin's rsync (in a Cygwin-Shell) which worked fine. http://www.cygwin.com/