This is a simple batch file that automatically creates a backup of the server_level.dat into a local /backup folder, and uploads to any site you have FTP access to. It will record in the format of Day Date at TIME in 24-hour format. For example, on the 10th of July it saved Fri 07-10 at 0000.dat and uploaded to my site.
If you do not know what a batch file is, go to your Minecraft server folder, create a new text file, and add this:
cd C:\minecraft-server golfrt
for /f "tokens=1-5 delims=:" %%d in ("%time%") do for /f "tokens=1-5 delims=/" %%i in ("%date%") do copy "server_level.dat" "backup/%%i-%%j at %%d%%e.dat"
echo user USERNAME>ftpcmd.dat
echo PASSWORD>> ftpcmd.dat
echo bin>> ftpcmd.dat
echo cd DIRECTORY>> ftpcmd.dat
for /f "tokens=1-5 delims=:" %%d in ("%time%") do for /f "tokens=1-5 delims=/" %%i in ("%date%") do echo put "backup/%%i-%%j at %%d%%e.dat">> ftpcmd.dat
echo quit>> ftpcmd.dat
ftp -n -s:ftpcmd.dat HOST
Obviously, if you have a webhost you have FTP access to you will want to change the USERNAME to your username on that host, as well as PASSWORD to the relevant password. If you start in a non-public directory you'll want to change the DIRECTORY to the relevant folder you will be hosting the saves to. As for HOST that will simply be the IP or hostname you'll want to FTP to.
Now click File > Save as... For Save As Type choose "All files" and for File Name type in "backup.bat"
The next part is the easiest. Just add a windows task scheduler event to run your backup.bat at whatever time interval you want, and set it to run indefinitely.
Note: Yes, I'm aware there is an 'automatic' backup utility posted that requires .NET. Yes I'm aware most can run it just fine. However some reason for Windows 7 and some Vista users it won't run, and int he event you want to upload the backups to an online source so others can view when you change theme or whatever, this is a good alternative. It's simple, requires no extra resources and can be shared with others. It's also good in having the community (or just your users) help find a good save file before a server gets bombarded in griefers, as I've experienced myself.