So finally Cisco has released their coveted IOU (IOS On Unix) that has been internal only to Cisco for many years. In a nutshell, it is an emulator that can run any normal IOS code as it would on actual equipment.
The catch now is that they are releasing it under Cisco Learning Labs, and you can't just download the software yourself to use, you must rent labs like you would for an actual rack of Cisco gear for IE studying. Still not good enough Cisco.
Currently, they only have labs for CCNA ICND2, CCNP ROUTE, CCNP SWITCH, CCNP TSHOOT and CCIP MPLS, which will cost $75 for 25 hours (only $50 for CCNA lab). Additional 5 hour blocks can also be added for an additional $20.
More information here: