I ran out of room in my VHD image (for VirtualPC 2007) I've been using while building a new image for my current project. Blogging it so I don't waste too much time looking for it the next time I need to do this.
I was able to expand my VHD using the following:
Use VHDResize to increase the size of the VHD disk. Important note, which I missed the first time (since I didn't RTFM :()), this does not extend the partition.