Sure thing, i don't think you'd have any problems with a 2nd gen ipod touch. I can try it out later today when i get home, i'm fairly certain i've got a 2nd gen ipod touch somewhere.
And if you shop around the ATH-M50s can be had for a good price too. I believe there was a post in the deals thread a couple days ago.
For the sake of information, there are a couple really small/lightweight/cheap amps/boosters available. For example the fiio
e5 or
e6, although you probably already know of them. They may not be top-tier amps, but they can take up the slack your ipod may have, and you can drop either of them in your pocket with your ipod touch and a small LOD and hardly notice.