Generating Strong Passwords On PHP

I use the following snippet of code to generate passwords for my users:

md5(uniqid(mt_rand(), 1))

This returns a 32 character string, which is a hash of "uniqid(mt_rand(), 1)".

uniqid (string uniqid ( string prefix [, bool lcg] )) is a nice function that I discovered which generates unique strings. I prefix it with a random number and set the second parameter to 1 in order to add some entropy. This makes results more unique.

Note: When using PHP versions prior to 4.2.0, the random number generator needs to be seeded. The following snippet is generally accepted as the seed to use.

mt_srand((double) microtime() * 1000000);

Here is a few examples of the sorts of passwords that this code generates:

97dfafa794
8b8a16d017
90b18f296c
dd7e177c5a
7a96fed079
As you can see, very random (ignoring the fact that it only uses 0-9a-f (...*cough*)).