I have been trying to install using packages the drivers for the printer of a friend: a Canon IP 1700 PIXMA- It proved more complex than once thought, so she has been without a printer for a while. I had tried as suggested in a few web pages to use the driver of the IP 2200 using alien.
I finally managed after I first removed all the drivers I had installed for the IP2200 and then reinstalling IP1800 drivers for debian from some web page. So at least, she has a printer right now.
Edit: Note that packages for the version 7.10 of ubuntu can be downloaded
there.
It seems that for the Hardy Heron (aka Ubuntu 8.04) some other drivers exist, see this
page.