I set up a Sharepoint (WSS) site with forms-based authentication (FBA) via ASP.Net membership provider - I can change user's passwords with the ASP.Net config tool. But I want them to be able to change their own password. Should be something obvious that I'm just not seeing, right?
You want the External Collaboration Toolkit (it's free), which you can get here: http://www.microsoft.com/downloads/details.aspx?FamilyId=D9AF2C25-989C-45C4-8008-1F15722190ED&displaylang=en
It includes some web parts that will allow users to change their passwords, workflows for users to request accounts (which are routed to an admin for approval), etc.
It's actually pretty sweet (and the cost is right)!