There's a product we use from SharePoint Solutions called ExCM (Extranet
Collaboration Manager). It lets you add/remove/edit users in the auth DB, reset
passwords, and delegate "Site Sponsors" so an "admin" user of the site can
manage their own users without going through IT. But it's kind of expensive,
around ~$3,500/WFE with installation.

There's a free solution on cks.codeplex.com to do very basic things but it
doesn't support SP 2010.

There's another SP 2010 product at
www.devit.eu/.../...0-forms-based-authentication.a\
spx
I've never used it but it's ~$1,000 USD and is licensed for the whole farm
rather than per WFE. Looks "good enough"??