I have a couple clients who don't want the login control on the site (don't ask me why.) Here is one way to create a login URL:

Go to the Host settings and expand the Friendly URL Settings.

Modify  Rule one of the current rules:

• Original Match
  • [^?]*/TabId/(\d+)(.*)
• New Match
  • [^?]*/TabId/(\d+)(.*)/default.aspx

Add New Rule

• Match
  • .*/TabId/(\d+)(.*)/Login.aspx
• Replace With
  • ~/Default.aspx?TabId=$1&ctl=Login&returnurl=%2fdnn%2fHome%2ftabid%2f$1%2fDefault.aspx

To Use: go to any page.  
Make sure that the URL has the tabID in it.
i.e.  Correct: http://clickandcreate.us/Home/tabid/102/Default.aspx
      Incorrect: http://clickandcreate.us
Change "default.aspx" to reade "login.aspx"
Your link will look like:
     http://clickandcreate.us/Home/tabid/102/Login.aspx
This will let you login and the redirect you to the current page.

Note there is already a rule for logging out: ".*/TabId/(\d+)(.*)/Logoff.aspx"  This take a URL in the form of:
      http://clickandcreate.us/Home/tabid/102/Logoff.aspx
and automatically logs the current user out.