Note: crossposting this in both debian and raspbian forums as it's relavent to both groups.
I've just put together a new virtualbox dev vm for debian and raspbian.
This vm uses qemu in "user" mode, this is far more efficient than using qemu in "system" mode as it avoids emulating the hardware kernel and drivers.
The vm is configured with 1 gigabyte of ram but I would reccomend increasing this if you have lots of ram. The kernel supports PAE so it should have no problem with large ammounts of ram..
There are three chroots, /chroots/squeeze-armel /chroots/wheezy-armel and /chroots/wheezy-raspbian, /proc and /dev/pts are mounted in all chroots, build-essential and debhelper are installed, a policy-rc.d is in place and locales are configured sensiblly.
to login use username: root password: root
The host system is ubuntu precise and was chosen because it's a LTS release and it ships with a nice modern qemu (unlike debian squeeze which is getting rather long in the tooth).
http://archive.raspbian.org/qemu/rpi-qe ... ev.tar.bz2