telnet or ftp to a remote machine
Yeah sure.
If the remote machine accepts telnet connections from outside the firewall and has a telnet service running, just (I assume you are a Windows user) open up a command prompt and
C:\ telnet machine.example.org
You most likely will need a username and password to get in, unless they did not set it up for username/passwords.
To ftp to a remote machine, once again using the command prompt.
C:\ ftp ftp.hostname.org
//sometimes ftp ww.hostname.org
once again you will probably need a username and password, but if the machine accepts anonynous users use.
username: anonymous
password: [email protected]
Hope that helps a little.