On my train commute, the Ipod and Etymotic ER4P serve me well. Pretty good isolation (I sometimes just have them on without music when I want some quite). The Ipod can drive them to plenty loud levels even with the ERP4P/S adapter, but it sounds strained. I ordered a fiio amp to see if it makes an improvement (since it is ~10$ and weighs less than the AAA battery, it is almost qualifies as non-amp for most intents and purposes so I slipped it in).
Hi there. This is my first post to the forum ... hope you'd find it interesting. you can replace the hard drive of the ipod with a compact flash card (a 30g a-data goes at newegg these days for less than 100). For ipod mini, you just replace it. For 5.5g you need an adapter. check out Tarkan Akdam’s BORED I ordered one from him (haven't ordered the cf card yet). Shipping from UK was pretty fast. Cheers, Erez