I've been trying out CloudFlare to try to speed up the site a bit and so far, it's working great! It's also handy because I can use it to bypass 1and1's 5 subdomain limit because I'm using CloudFlare's servers.
Unfortunately, this means I've had to reconfigure a bunch of stuff. I've already noticed that some things are breaking (https stuff) and I'm trying my best to fix them, but sometimes it's difficult to pinpoint the source of the problem.