What is it about Ghostbusters and steampunk? Well I suppose the first isn't really steampunk per se, it's a retro-refit. What if they'd made Ghostbusters in the '50s?
Here we have the ad for the League of S.T.E.A.M. a bunch of clever gents who have combined their love of steampunk with a ghostbusters theme. I've added a link to their homepage on the sidebar, have a look, there's a lot of other cool videos there.