> but still I'll panic pretty badly if my laptop is ever stolen, because in there, somewhere, is probably a plain text password stored in a file
You really should consider using using whole disk encryption like FileVault or PGP-WDE. Encrypting a single directory or a home directory is not a good solution.
I use TrueCrypt. I put all the files I create into a single encrypted volume. I copy that encrypted file to a thumb drive and bury it in the backyard. I don't encrypt the entire hard drive, though, something I should probably do to protect the recycle bin and whatnot.
You really should consider using using whole disk encryption like FileVault or PGP-WDE. Encrypting a single directory or a home directory is not a good solution.