I find the following quite helpful in day to day Windows administration.

Unlocking an account:

net user /domain /active

Thus, if the domain account jdoe is locked out the following example would unlock the account.

Example:

c:\>net user jdoe /domain /active

Changing a user's password:

net user /domain

If you put a * for the password you are prompted for the password.

Example:

c:\>net user jdoe * /domain

Checking domain account information, status, and group membership:

net user /domain

Example:

c:\>net user jdoe /domain