I think a semi-portable rig would be your best bet. The new 2007 Headroom Desktop portable and an Edition 9 might be the best you could do. The Edition 9 is pretty portable, and it has pretty good isolation. I think it would be much more versatile than the GS1000, and I'm betting it sounds better too (I have an Edition 9 and love it!). The 2007 desktop portable has a built in lithium battery, the home module, and a slightly modified version of the Desktop DAC. The only thing is that I don't know how the headroom amps perform with low impedance headphones (such as the Edition 9 or Grado GS1000). It's possible that you might be better off with Larocco's new LISA or whatever it is . . . I hear it sounds really good. That amp is about $500, and you'd need to get a portable DAC to go along with it. And either of these options would require a source. A laptop would be great, but if you want to be able to walk around with your rig, the iRiver DAP with the optical output would work well. If you like to take your gear along but won't be using it for running or anything, I firmly believe a setup like this (and definitely involving the Edition 9, if it's to your taste) would be your best option. This is sort of my situation: I like to take my gear to the library with my laptop, but I didn't want to compromise on sound quality for battery power and compactness, so instead of a portable amp/dac, I went with the somewhat transportable Corda Opera. I can just stick it in my laptop bag with the Edition 9 (in their case) and walk to the library when I want to do some studying over there.