I've signed up for the ProBlogger "31 days to build a better blog challenge". It starts April 6th. (It was supposed to be today but it's been delayed.)
I don't know whether it'll improve my blog or not, but I'm willing to put 31 days into it to see what happens!
If you are too, sign up at http://www.problogger.net/archives/2009/03/25/31-days-to-build-a-better-blog-sign-up-here/ and then we can work on our blogs together. :)