ssh -X FTW

Ubuntu 10.04 image on VMware Fusion with 1 Gb allocated to it gives great almost a native feel in terms of performance. But thats only when you have some ram to give to it, for other times its ssh -X and debian testing on netbook for PyQt work :)

Netbooks are one awesome solution for the need of headless boxes if you're willing to shell out 15-18k. Or even second hand ones for around 12K