ssh-pageant is an SSH authentication agent for Cygwin that links OpenSSH to PuTTY's Pageant. It acts very much like ssh-agent, except it leaves the key storage to Pageant. You can use ssh-pageant to automate SSH connections from the Cygwin shell, and I find this is most helpful for those services built on top of SSH, like SFTP file transfers or pushing to secure git repositories.
See the README and the manpage for more details.
The latest release is ssh-pageant 1.1 (source). Please report bugs or suggest enhancements via the issue tracker.
The project is hosted on GitHub at cuviper/ssh-pageant. You can clone the latest sources with Git by running:
$ git clone git://github.com/cuviper/ssh-pageant
Josh Stone (cuviper AT gmail.com)