When fogetting assigned login name rather than password

[Richard Owlett <rowlett@cloud85.net>]

I'm running a series of experiments installing multiple versions 
of Squeeze on a dedicated machine. The machine is dedicated to 
experimentation and the lifetime of any install may intentionally 
be only hours or days.

The complete hard drive is wiped at least once a month. I 
consistently use my name as the login on the first install of any 
series. The login of any subsequent install will be a mnemonic 
associated associated with the current experiment.

I just tried to bring up an install without a GUI. I had 
forgotten the login name I had assigned a week ago. I solved the 
immediate problem by rebooting to the install on sda1 and using 
it to examine /etc/passwd on sda7.

If another OS had not been available but I knew the root 
password, is there some way I could have gained access as root?

TIA