I was thinking of creating a list like this of all the sites that (most likely) store passwords as plain text. I'd get the list by doing a password reminder and seeing if they email me my password. Would be cool if that was added as a column here. I'd submit some sites.
That will tell you whether they send the password in clear, not whether they encrypt it. The only information you'll have is:
IF (they send you the password in clear) THEN (they don't use a one-way hash)
There is no other information to be derived from this method of checking.