What is a site collective?

Well, it's a collection of sites, hence the name, that are owned and/or operated by the same person.

What is the Perfect Imagination Network?

Perfect Imagination Network started out in 2005 under the name of LunaStar at http://lunastar.lilacwoods.net/, became Tangled Webs briefly, and finally reached it's current title about a year and a half after it was began. In early 2007, Perfect Imagination Network moved to http://blue-realm.net/ when the domain name was purchased as a birthday present for Shiralis.
Perfect Imagination Network is on its 4th layout design - the first layout was listed as Tangled Webs, with an abstract layout; the second layout changed it to Perfect Imagination Network, and used an image of anime character Kinomoto Sakura from Cardcaptor Sakura; the third layout used an image of a character from the anime Sister Princess. The current layout uses the main graphic from a wallpaper made by Shiralis.
PIN is a collection of sites owned by Shiralis, such as fan listings, fantasy fiction stories, and a graphic design studio. Saiyuri Designs is the graphic site for Shiralis, and there are various wallpapers, transparant .pngs, brushes, and free layouts that are available there. NOTE: Saiyuri Designs is currently down, but will be up again shortly. PIN is also used to list the fan listings that Shiralis has joined.