How does Stack Overflow generate its SEO-friendly URLs?

Question

What is a good complete regular expression or some other process that would take the title:

How do you change a title to be part of the URL like Stack

Answer 1

Now all Browser handle nicely utf8 encoding, so you can use WebUtility.UrlEncode Method , its like HttpUtility.UrlEncode used by @giamin but its work outside of a web application.