Setting up your own blog is pretty easy, but assessing whether it's up-to-date and performs OK is another matters. Is My Blog Working? rates your site on a number of criteria, including whether your hosting and server software is up-to-date and how quickly pages and feeds load.
Just enter your blog address into the site and it will generate a report rating everything from the speed of pages to how many references are found on Google and Bing. Fixing problems might be trickier if you don't want to move hosts, but it's a useful first step.
Got your own favourite tool for checking on your blog's health? Share it in the comments.