One point I'd like to make, don't use the same password for this as you do for HN. Now I don't think anything bad is likely to come of this it's just not a great idea thats all(using the same password that is).
Typically hash's are calculated using something like: $hash = sha1($password."secretcode".$username); - none of which are random.
If you were to add a random number into that like this: $rand = rand(1,99); $hash = sha1($password.$rand);
Now you can't do if($hash1 = $hash2) { loginSuccess(); } because you will never know what random salt was generated for the original hash.
Not true, a plain hash can be compromised with a brute force attack. To do this all the entries in the dictionary(used in the attack) must be hashed using the same hash algorithm.
If each password entry is hashed with a random salt(with the salt being kept for password comparison) the attacker must rehash the entire dictionary(not a computationally cheap thing to do) including the random salt, for each and every password.
This doesn't make it impossible to brute force a hash+salt, but makes it a LOT more expensive and time consuming.
At least this is my understanding of the whole point of random salted hash.