The idea of a breadcrumb bar in the Windows Explorer is fantastic – it’s one of my favorite features of Windows Vista. It’s not “killer,” but it’s certainly useful – and it’s also available for Windows XP through the free Explorer Breadcrumbs extension. That’s one less reason to upgrade to Windows Vista when it goes gold in a few weeks. I installed the Vista RC1 refresh yesterday and discovered only incremental improvements. I’m having sushi with Dave Vronray in the near future – where I’ll be able to point out thousands of Vista UI oversights (in person).