[Blind-sysadmins] Any Accessible Way to do Cisco Router Simulation

I fear I know the answer to this, but I'd rather not assume. I'm working on my CCNA course, and am curious if there's any way at all to do router simulations of any sort without having a physical device. While I can use the devices at where I'm taking the class, there are times I want to try something without having to wait to go in and use them. Thanks in advance for any suggestions. Nehemiah Email/MSN: nrh@n-republic.net Twitter: miahtech Skype: trekky-techie AIM: NehemiahRepublic