I've been using Visio to mockup to design mockups and wireframes for sites, but I'm looking for other tools to help with the design process. I've been playing around with MS Expression Blend and SketchFlow, but I haven't found reusable components (i.e. libraries) pre-built for SharePoint.
Has anyone developed them, or found them somewhere?
Any other recommendations on UI/UX tools? Tools that can be shared with a team and saved on-premises are preferred. Intranet Factory? Balsamiq, Axure?