Update
I experimented with a the Users Ultra plug-in for WordPress but I decided that it was not useful for my website, so I deleted it.
Original post
I have added a WordPress plugin, Users Ultra, which allows registered users of HunterThinks.com to send non-encrypted messages to other registered users. The plugin has some other useful features, but most of them make administration easier rather than change the user experience.
It seems that there are at least two different login screens now.
and
If I had more time, I would test these thoroughly and I make only one screen. I would love for someone to help me with little tasks such as this one: tying up loose ends on the website. Send me a message if you want to do this.