If you want to have a control in autonaming the posts in blogs you can use this module.
The module allows you to configure which chars will be removed or replaced from the Name (if not present than from Subject) in weblog post Name property used for "nice" URL.
There is one special tag - on the same level as replace/remove - with name czech: when you use this tag and set its value to true then each czech char [ěščřžýáíéúůďťň] will be replaced with an equivalent without wedge or accent.
This release is only for ASP.NET 2.0 website
Hope this helps.