External HD with a Filevault 1 home directory, readable from Lion? I have the HD from my old Snow Leopard Mac containing my old home directory encrypted with Filevault 1.  Can I mount this HD in a USB enclosure as an external volume on a new Mac running Lion, and read the contents of my old Filevault 1 protected home directory?  Do I need a Keychain item, or anything other than my old login password or admin password?
Yes you can. I've used this to recover data from an old Macbook Pro hard disk when I couldn't boot the computer itself using a SATA-to-USB caddy.

Once the old drive is attached, first you need to locate the .sparsebundle file containing your encrypted home directory on your old hard disk. This lives in a hidden folder

/Users/.&lt;username&gt;/&lt;username&gt;.sparsebundle 

in my case this would be 

/Users/.binarybob/binarybob.sparsebundle

Once you've found this, you can mount it using the terminal with

hdiutil attach binarybob.sparsebundle

You will be prompted for your password. Once you've entered it correctly, your home directory will be mounted and visible as a drive from the Finder (and rooted  at /Volumes/binarybob)