Just started playing with Copernic’s new free Desktop Search tool and it may just be a keeper.
It produces typically large indexes (around 700MB for a 10GB dataset on my machine) but unlike Blixx there doesn’t appear to be any ongoing performance hit. Searches emails, files, music, pictures, web etc. And very fast. What’s more it segments search results by time periods, which is uber cool. And did I mention it’s free? Definitely worth a look.