Sometimes you want to get a document off a computer that is using FileVault, only to find that after sshing in, all that is left of your user directory is a username.sparseimage file. All is not lost, you can still get to your files using the following command via the Terminal:
~here: ssh remotecomputer
Password:
~there: hdid -stdinpass /Users/username/username.sparseimage
You should now type in your password, but be careful when you do this, your password will be echoed in plaintext. Type in your password, and then null terminate it (hit control-V then Shift-Control-@), then hit Return, and then Control-D. Your user directory will then be mounted in /Volumes/username/ (not your ~username directory, for some reason).
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040225211826452