How can I mount SFTP/SSH in Finder on OS X Snow Leopard?
The best solution I've found today (2017) is to use Homebrew and Cask to install osxfuse and sshfs:
brew install --cask osxfuse
brew install sshfs

And then:
sshfs username@hostname:/remote/directory/path /local/mount/point -ovolname=NAME

It works! :-)