Some more good news. I managed to get other programs, such as VNC Viewer, to run through SSH SOCKS proxy.

I used the Debian Sid "armel" tsocks package. I installed everything manually using my Ubuntu desktop and sftp; Application Manager complains that the Debian package is "incompatible". Perhaps someone who knows how to package stuff for the N800 could repackage this?

The /etc/tsocks.conf file needs only two lines:

server = 127.0.0.1
server_port = 3210

The server_port is whatever you put after the -D in your ssh line. I use 3210, you can use whatever you'd like.

Then you just type:

tsocks vncviewer

and it's like you're inside your own home network.

EDIT: tsocks is available in the debfarm repository