After unsuccessfully implementing an integrated logon page within my WordPress sites, I discovered today this great plugin at Blue Anvil that allows login through a sidebar widget. Initially, I had trouble setting it up because it kept pointing to the server name minus port (my IIS and network setup prohibits this). After some tweaking in the code to make the path include the server port, I managed to get it working right. Thanks, Mike at Blue Anvil!
Looked for the following code:
$_SERVER["SERVER_NAME"].$_SERVER['REQUEST_URI']
And changed to:
$_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER['REQUEST_URI']