I did, it works out of the box. You need to install the tools like iproute and such to configure tunnels though.
I've used aiccu to get my SixXS tunnel working. I needed to compile it on scratchbox first as the debian armel package didn't want to install. You can find the deb package for N900 here: http://fournier.nl/aiccu_20070115_armel.deb. After creating a valid config file, it works out of the box.