P.S.I.entology was the only DVD release from the British band Pitchshifter. The DVD was the second release from PSI Records which is run by members Mark Clayden and J.S. Clayden. The DVD was released ostensibly as a "thank you" to the band's loyal fan base. The release prompted the band to reform after their 2003 split to take part in a seven date tour of Britain in October of 2004. This was the last tour the band played together until the recent announcement of a 5 day tour of the UK to celebrate the birthdays of two of its band members (J.S. Clayden and Jason Bowld).