I was typing the /mnt$ -- I guess you'd expect that would
give me an error, but I'm pretty much ignorant of these things.

> Given the layout of your disk, you'd want:
>
> ubuntu@ubuntu:/mnt$ sudo mount /dev/sda2 /mnt

Nothing looks to be too full --

Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 354592 33788 320804 10%
/lib/modules/2.6.20-15-generic/volatile
tmpfs 354592 33788 320804 10%
/lib/modules/2.6.20-15-generic/volatile
varrun 354592 108 354484 1% /var/run
varlock 354592 0 354592 0% /var/lock
udev 354592 104 354488 1% /dev
devshm 354592 0 354592 0% /dev/shm
tmpfs 354592 12 354580 1% /tmp
/dev/sda2 11282776 2457244 8481664 23% /mnt

What else might keep me from logging in? I'm using the live CD to
post this, BTW...