I had QtQemu installed until a few days ago. It was slow and I could not see what the virtualisation fuss was all about.
On Saturday I got getvirtualbox (thanks Pinoc). I am very impressed.
I have now banged in half a dozen different systems, used the bridging network thing, and have been using ssh to access several virtual machines. Each machine runs fast and works much better than I expected.
Quite an eye opener.