When The Two Towers was released in cinemas, many people disliked (and some hated) the changes to J.R.R. Tolkien's story. That motivated someone to create The Two Towers: The Purist Edit. Somewhat similar to the Phantom Edit, it is a re-edit of the theatrical version that deals with most of the changes that people disliked (some described in the StrawberryFrog's writeup) to make a film that follows the book plot more closely. This new version is not shown in cinemas, but instead is available on the eDonkey P2P network.
To name just the biggest differences: there are no Elves at Helm's Deep, Faramir is a good guy again, Ents don't refuse to help, Arwen doesn't leave Middle-Earth, Gandalf does not exorcise Saruman from Théoden, etc. As a result, this version is about 40 minutes shorter, but for some people it is superior to the original release. The changes are cut out seamlessly and the sound track is carefully re-synchronized, so the only way to notice the changes is to compare the Purist Edit with the original. In some places The Purist Edit manages to completely reverse Jackson's changes and reconstruct the original Tolkien's storyline.
Film length: 2 hours 15 minutes (the theatrical release is 2 hours 59 minutes, and the extended edition DVD is 3 hours 42 minutes).
Major changes (out of about 30 changes totally):
- The ents don't initially refuse to attack Isengard
- The group of elves led by Haldir doesn't appear at Helm's Deep
- Gimli is no longer the plucky comic relief
- Faramir doesn't decide to send the Ring to Gondor as a "mighty gift" for his father; he also doesn't take Frodo and Sam to Osgiliath
- Frodo does not attempt to give the Ring to a Nazgûl
Sources:
http://forum.sharereactor.com/viewtopic.php?t=110181
http://slashdot.org/comments.pl?sid=61792&cid=5797165
http://www.bits.bris.ac.uk/mxcl/blog.php?bSHOW=48