David Fletcher mentions Utah State Representative Steve Urquhart's blog (it didn't want to open for me within Firefox, but loaded fine with IE) in his post, "Representative Blogging".
I think it would be good if more Representatives had a blog. I think it could be a great tool for them to communicate with many of their constituents. I am not aware of any of Missouri's Representatives openly advertising a blog, of course, that does not mean that they do not have one. When viewing the roster and clicking on the Representatives name there is a location for the Representatives personal e-mail address as well as their personal website. Several do have their personal e-mail address listed, but I only noticed one having a personal website listed and that individual is the Speaker of the House, Rod Jetton (state listing/personal site).