I don't know if it's a change in the areas I'm working in, or because my network has reached some sort of critical mass, but I've found myself doing a lot of introducing over the last year or so.
It's strangely satisfying to get folk who should talk, to talk.
http://www.avc.com/a_vc/2009/11/the-double-optin-introductio...
it's the right way to go about doing this, so you don't inadvertently waste people's time, leak information about something that wasn't public, etc.