I use a netbook, Asus eee pc, 1005HA.
I couple this with a Cambridge Audio DAC Magic (connected via USB, thus avoiding the soundcard in the netbook) and a Cambridge Audio amp.
Software for the music library is iTunes with windows Audio session enabled.
The system works great, but can suffer a little from fan noise, especially if one enables the iTunes visualiser, this really cooks the processor.
Otherwise it's fine, works very well indeed.