How can I automate an SFTP file upload to my web server?

You can use http://www.expandrive.com/ or another SSHFS system to make your remote SFTP server look like a local disk on your Mac. Then you shouldn't need to do any scripting—just save in the appropriate folder directly.

https://code.google.com/p/lsyncd/ is what you want if you don't want a dependency on dropbox.

sounds like a job for applescript.

I don't have 10.5.8 (I'm on Mountain Lion), but the following should work: Open Automator Select Folder Action as the new type of Automator script The action you want is called Upload and it is provided by Transmit, fill in the necessary details Set the folder to be the folder that Kung-Tunes dumpts the html file to Profit! (If you don't have Transmit [you did mention it] you can do this just as well with a bash script and ssh keys. If 10.5.8 doesn't have Automator [not sure when it was introduced], you can do this with cron firing a bash script and ssh keys.)

Or automator. Automator can set up an action on a folder to do many things, including "Run Shell Script." The shell script can do the ssh/transfer and can delete the file in the action folder so that it can do the next thing on the next generated file. Or, if you're a bash kind of person, you can use the unix utility "rsync" and a cron job that fires every five minutes. Or if you don't want to sync but just want to copy files, use "scp" in an every five minute cron job.

I wish I were applescript savvy, but alas, I'm a point & click end-user of the lowest sort. I can read manuals, though. I just tried Automator using the "Get Specified Finder Items" and the "Upload" (Transmit) actions, but it sticks at the "overwrite file?" dialog, and I don't see how to make it run automatically every time the file is modified. I understand the rudiments of the bash command line & rsync, but have never run or written a shell script in my life.

assuming the file isn't large enough that you wouldn't mind false positives you could just upload it every minute using cron. A http://hints.macworld.com/article.php?story=2001020700163714. If automatically logging in is an issue you can look into http://micheljansen.org/blog/entry/123

This doesn't answer your direction question, but have you considered using something like Dropbox or another cloud storage platform? That's really the most straight-forward way of keeping files in sync, and it sounds like that's the problem you're trying to solve.

I don't see how to make it run automatically every time the file is modified I expect you could do this with http://www.macworld.com/article/1167157/automate_tasks_with_folder_actions.html