This is the 2nd song on the album the Sky moves Sideways.
It's very simple to play but since there aren't many Porcupine Tree tabs up I thought I'd post it.


G------------------------|
D------------------------|
A-44---44---44---44---2~-|
E------------------------|



G----------------------------|------|
D----------------------------|------|
A-45/7875-45/7875-45/7874-|--4-5-|
E----------------------------|-7----|



That's it.  Just get the timing right and you have it.
This is a Porcupine Tree song not mine, rock on.