putty itself is based on SSH, which should be installed on your 11.10. At a shell type:

ssh username@hostname

The machine you're connecting to will need to have an SSH server running. You can set one up quite simply using the following code:

apt-get install openssh-server

To transfer files to and from a machine, you can use SFTP (implemented as psftp in the putty suite) or FTP, but both SSH and SFTP/FTP operate more on a client-server model (one machine serving, many connecting)

As maythux points out, if you are looking for a file sharing solution (many serving, many connecting), have a look at SAMBA, NFS or the Nautilus sharing option.