Just a Suggestion...
I've only been a LJ user for less than a month, but I love it already and was going through withdrawal symptoms this weekend. I have a free account so I thank you for all the hard work you've been putting into LJ.
I know the $$$ is limited, but have you looked into using Solid State Solutions to bust LJ's I/O bottlenecks? I'm not trying to make money off LJ, but I work for BiTMICRO NETWORKS and we have a product called the E-Disk. It's a Flash based solution, which is 4X cheaper than DRAM, but could solve your bottleneck problem as well. I don't want to sound like a sales person, but just wanted to help out!
I know the $$$ is limited, but have you looked into using Solid State Solutions to bust LJ's I/O bottlenecks? I'm not trying to make money off LJ, but I work for BiTMICRO NETWORKS and we have a product called the E-Disk. It's a Flash based solution, which is 4X cheaper than DRAM, but could solve your bottleneck problem as well. I don't want to sound like a sales person, but just wanted to help out!