For your account options, you can allow livejournal to mangle your email address some requests userinfo.bml?user=blah, so scripts to harvest email pass over it. However, you lose the ability to click on the link, and have your favorite mail client open up and create a new message with their name in the to: field.
This patch is untested, but I did write some proof of concept code in perl and it passed. I simply created a variable called $email, set it to firstname.lastname@example.org and had called it through a http request.
I was wondering if anyone with a goathack account would be willing to help me do some testing and allow to run a few test to make sure everything is working properly, and everything looks right.