There was a program named /usr/bin/magnifier in the gnome-mag package which allegedly provided magnification under GNOME2, but it wasn't started by Accessibility services correctly, and even if started manually, it still didn't work. In Oneiric, that package exists but is not installed by default and in any case isn't apparently used by Accessibility. I don't know what Ubuntu's solution to magnification is under Unity or Classic desktops in Oneiric.
There was a program named /usr/bin/magnifier in the gnome-mag package which allegedly provided magnification under GNOME2, but it wasn't started by Accessibility services correctly, and even if started manually, it still didn't work. In Oneiric, that package exists but is not installed by default and in any case isn't apparently used by Accessibility. I don't know what Ubuntu's solution to magnification is under Unity or Classic desktops in Oneiric.