Lightbox Technologies has a tool that I have been told about called Lightgrep. It has been added to the current versions page of the blog.
Lightgrep is, and I quote, "a Perl-compatible regular expression search engine for forensics that's several times faster than EnCase's keyword search." It looks to be a promising add-on for EnCase!
I look forward to trying it out!
Check them out at Lightbox Technologies