W3 Total Cache is an amazing, free WordPress plugin that when configured optimally results in WordPress blogs loading much faster, like this one.
If you want to view the home page in WordPress, it normally runs a PHP script, opens the database, populates the page with the data, then presents it to the viewer. If you have 10 (or 100 or 1,000) simultaneous readers, it does the exact same thing each time, which puts a big load on the server and is duplicated effort. A cache writes the home page to disk as HTML and presents that to readers, which takes vastly less resources and is much faster. If the home page changes, it simply re-writes the cached page.
W3 Total Cache does that, and much more. It has database, object, and browser caches as well as page caches, and eight tabs of highly detailed settings, which can be intimidating at first. I highly suggest reading Install and configure W3 Total Cache in 7 easy steps, which walks you through the process (45 page PDF on Scribd)
It also has Minify, which strips unneeded blank space, comments, and line breaks from HTML, JavaScript, and CSS, cutting down on the size of pages sent to browsers. This is one of the more involved options. I advise doing the others first, then this. If you do a View Source on this home page, you’ll see that the code is mushed together with Minify.
If your blog is on a shared server, disable Database Cache and Object Cache, as they say it can actually slow things down. Once I did that here, load times became much faster.
Polizeros is now getting load times of 2-3 seconds, and that’s because of W3 Total Cache. I highly recommend it for any WordPress blog.
Download W3 Total Cache from WordPress.