yehey, it sounds you are looking for a telnet client, your device would be the "server" in this case. Perhaps you are looking for a jumping spot or a way to hide who you are....then you can use a proxy. I dont know how long idle can get by default (5 minutes maybe?), but I think it is a function of "exec-timeout" command on the line:
line vty 0 4
exec-timeout <seconds>
Does that help?
If telnet is not enabled on your router, than that guy is out of luck trying to telnet...what exactly did you see?
-B