There is also an easy way to connect to your n900 remotely when you have set everything up according to greygoo's howto. What you need is a fixed ip and a ssh server on your laptop's side. This might also work with some dyndns service, but I'm not sure of that, since I have never tested it with dyndns.

Just open a remote tunnel from your n900 to the server running on your laptop:

ssh -i yourkey -R localhost:3333:localhost:22 someuser@server.ip

The good part is that this tunnel works regardsless of the ip of n900 (that is: you don't have to know it) and the tunnel works well even over gprs connection.

to connect to n900 from your laptop:

ssh -p 3333 user@localhost

Now all that is left to do to be able to connect to your n900 when it is e.g. lost, is to set up a daemon to connect to the server periodically or to setup autossh (don't know if autossh is available for n900) to keep the tunnel open at all times.

Oh, I forgot to mention this:
Before you can use the reverse tunnel to connect to n900 without password (the -i yourkey part above) you need to create a keypair on the n900 and copy n900's public key to the laptop's authorized_keys file:

on n900 do:

ssh-keygen -t rsa

scp id_rsa.pub someuser@server.ip:./ssh/n900.pub

on the laptop do:

cd .ssh/

cat n900.pub >> authorized_keys

propelli