Diigo is an online collaboration tool that has some of the web capture & edit tools of Snagit, with groupware thrown in. It claims to provide “a ground-breaking collaborative research and learning tool that allows any group of people to pool their findings through group bookmarks, highlights, sticky notes, and forum.”
Seems like a great tool to use for sharing ideas about improving Virtual Home – not only could we archive screen captures of websites with features we admire, but we could post proposed changes to VH for the group to discuss.
Their tagline is “Research, Share, Collaborate” – sounds familiar.
BioMed 2.0 
I played around with Diigo a bit – it actually stores bookmarks rather than screenshots, so you can’t show only the site feature you want to discuss. And you can’t actually edit as you can with Snagit, just highlight text or add comments. Still might be a good tool to gather examples for discussions of navigation, for instance.