I think your best bet would be to implement the free iFinity URL Rewriter for DotNetNuke. At the very least, you should be able to achieve the following:
http://snit.us/Home/CN/1/RE/23/United_States_Missouri
If you're using IIS 6, you'll want to enable extensionless URLs in IIS. If you're using IIS 7, you should not need to make any changes.
To set it up, you'll just need to add the DLL that iFinity provides to your site's bin directory and then follow the instructions that came with the download for configuring your web.config (make sure to make a backup copy of your web.config for safety and convenience).
Here is an example configuration that we use on dnnGallery.net:
<add name="Ifinity.FriendlyUrl" type="iFinity.DNN.Modules.FriendlyUrl.DNNFriendlyUrlProvider, iFinity.FriendlyUrlProvider" includePageName="true" regexMatch="[^\+a-zA-Z0-9 _-]" urlFormat="HumanFriendly" redirectUnfriendly="true" doNotRewriteRegex="(\.axd)|(/DesktopModules/)" doNotRedirect="SearchResults;" doNotRedirectRegex="[.]*(/logoff.aspx)" pageExtensionUsage="never" parameterHandling="ordered" checkForDupUrls="true" forceLowerCase="true" redirectWrongCase="false" replaceSpaceWith="_" redirectDefaultPath="true" />