Guidance Software Inc. provides an opportunity to order a demo CD of Encase. The program itself is quite expensive, so, unless you need a law enforcement-level forensic tool, I would recommend finding a less expensive alternative for the time-being. The only businesses which I have worked with which have purchased individual licenses of Encase were businesses who specialized in data recovery, something which many far less expensive programs can do quite well. Do a search on Google for data recovery tools if you are interested in such a package.
PS: If you're trying to find the full version of Encase free for download, I suggest you go somewhere else. Many of the members of this site are software developers or work closely with software developers and do not condone software piracy.