I run my work back and forth between work and home sometimes. It works, but you need a large flash or hard drive. The newest VMware image (0.7) is almost 8GB and with a persistent drive space file, I'm often up over 10 GB. That takes a while to copy both ways; I end up using a portable HD.

Subversion would work for project storage. However, I often have settings I want to transfer -- Eclipse configs or the specific setup of supporting software. That could go into an SVN repo...I guess.

I'm rooting to a qemu image of a dev environment, like there is for VMware. I've heard rumblings that one is being worked on. That would be the closest to a portable SDK.