SSH Login Script

I have research a few things and have ideas about this, so for me to accept an answer, I will need a fairly detailed answer ( but I will award more points if needed to accomplish this ).

I have used public key based authentication with SSH before and though it is a good solution, it is not the right solution for this issue.  I have hundreds of server that I wish to ssh to serially in a script... I want the script to prompt me for a password like:

echo Enter your passwd
stty -echo
read PASSWORD
stty echo

and I want to be able to pass that result as an environment variable of parameter to SSH.  I have done this successfully with FTP and with RSYNC.

I had considered and played with ssh-agent ( which would have been great ), but I even after I ssh-add ed my private key, it continues to prompt me on the remote hosts for login, which just won't fly with having to login several hundred times.  So maybe I could also get along with a fix or better understanding of why my ssh-agent is not working properly, but I would also like to know if I can simply read input and pass it to SSH.