<p>I'm attempting to convert a home-grown login system to the standard asp.net login control included in .net.  I want all communication on the website for a user not logged in to be in clear text, but lock everything in SSL once the user logs in - including the transmission of the username and password.</p>

<p>I had this working before by loading a second page - "loginaction.aspx" - with a https: prefix, then pulling out the username and password by looking for the proper textbox controls in Request.Form.Keys.  Is there a way to do something similar using the .net login controls?  I dont want to have a seperate login page, but rather include this control (within a loginview) on every page on the site.</p>

You aren't going to be able to have your site as non-SSL, with a login box on every page, and then submit the username and password via SSL.
The only way to really accomplish this is to use frames of some sort. This way your entire page could be non-SSL, but the login frame would have to be SSL.
The usual ways of doing this is to either lock down the entire site with SSL, don't worry about having the username and password SSL encrypted and go to SSL after they log in, or go the frame route I mentioned above.