Site's been slow during peak hours lately. It's mostly because we need more webservers, but it's also partly due to a bug in our load balancing. We fixed the bug, we've tuned some of the most popular pages for speed, and we bought more webservers. They're on their way... 10 business days as of last week sometime.
We'll probably keep tuning the site until they get here, but there might only be so much more we can do, so please have patience. We're watching them almost non-stop, though, and doing lots of stats on CPU usage (since that's where we're hurting), looking for things to tune.