Lately I'm observing the roliferation of many websites that, upon entering your Hotmail username and password they'll inform you as to which contacts blocked you and which ones deleted you. Two questions:
1) As far as I know there's no way to tell who's blocking you, only who's deleted you. So are these websites a scam?
2) Are those sites legit? I mean, is it safe to input your username/password in their sites?

pft, doubt it, and why would you want to know anyway?

they do not work.
not even the deleted ones...
but plus can tell you who deleted you based on the reverse list....

so people just make these site because most people dont know that, get their email address and use it for dodgy purposes. =/

What these scripts do is this (basically)
Ask for you msn email and add the other persons email you supply
It will then get accepted or not by the person you want to know whos blocked.
If they do get accepted then the it will be accurate enough to tell you you're blocked (though not essentially)
However if they don't then they are not reliable at all

meh, there's a lot of sites like this and they tell you fake stuff, and use your account to advertise their website while you're offline so you don't notice. (They change your nick)

I've seen lots of them and many people (stupidly enough) put their passwords there..

There are some trusted ones:
http://blockchecker.msnfanatic.com/

Is know the above is safe. What you have to realise is block checkers just check your contact's status, but not if they have actually blocked you. However MSN Messenger had the option to disclose your status, and thus you can hide your status from anyone outside your contact list .

This is why block checkers are not very effective any more.