If you have a PowerShell script that needs to have the user enter a password, but obviously don't want the input echoing to the screen, try this:
$Password = Read-Host "Please enter password: " -AsSecureString
The variable $Password can then be passed along to commands that require a secure password string as a parameter.
Distribution Group Goodies
To add the ability to Send-As a group:
Add-AdPermission "Group Name" -user "User Name" –AccessRights extendedright -ExtendedRights "send as"
To delegate rights to modify group membership:
Add-ADPermission –Identity "name of distribution group" -User "name of user" -AccessRights WriteProperty –Properties “Member”
More details: Add-ADPermission.