LiveJournal and other sites using the same software don't provide a feed of your friends/reading page, something that has irritated me since I signed up. As more of your friends migrate to Dreamwidth or elsewhere (here's the latest reason) and more people thus suddenly want to keep up with multiple LJ-like sites, I'm guessing this will be an increasingly common irritation. These sites provide feeds of individual friends, but when you're reading a couple of hundred (making your feed reader's update cycle take forever), and/or you frequently edit the list, this is not ideal.
In late 2008 I thought
well, why don't I just put a feed merger on a cron job? and so I did. I've been using it since then, and have finally got around to tidying it up and releasing it. On the project page, you'll find the script and instructions. It's by no means a complete or universal solution: you need to have your own web hosting and be able to set up authentication. Still, a few people have kept asking me for this, so for them at least, here it is: Amaljamate.