I have ubuntu installed through vmware fusion on my mac. I tried to fire it up the other day but found that I’d forgotten my user password. Googling it got me http://www.psychocats.net/ubuntu/resetpassword
This worked, mostly. The only weird part was at the recovery menu (with the blue screen in the background) — when I hit “downarrow”, it treated that like I was selecting the currently-highlighted menu option. But typing “r” for “root” and then enter worked, and I was able to use passwd like the guide said. Now I can play around again, and I didn’t have to reinstall my virtual machine. Thanks, #lazyweb! Thazyweb.