If the last post was too simple and you prefer something a little more complicated, you can do what I did over ssh from my laptop to my Nokia N800 (where the Nokia is at 192.168.0.5 on my network):

ssh root@192.168.0.5 'cd /media/mmc2/apps;wget "http://nikosapi.org/software/panucci/panucci_0.3~pre0.4-2_all.deb"; apt-get update; apt-get install python2.5-gtk2 python2.5-gstreamer python2.5-dbus python2.5-hildon python2.5-gnome python2.5-mutagen python2.5-osso gstreamer0.10-plugins-bad-faad gstreamer0.10-plugins-ugly-mad ogg-support; dpkg -i /media/mmc2/apps/panucci_0.3~pre0.4-2_all.deb'

Mind you.. you'd still need to enter a password (unless you set up a keypair automated login) and you'll still need to hit Y and press enter at one point. I don't recommend this for most folks because it pre-requires openssh or dropbear, a remote root login and I usually suggest you understand everything being done before you just blindly do something somebody on the Internet tells you to do.

example: If you're happy and you know it, press ALT+F4!

IT'S A TRAP!!

My apologies for the distraction.