I'm not a huge Clive Barker fan - actually the only book of his I've read and thoroughly enjoyed was Galilee. But I do love his ideas. In this respect he's rather like China Mieville: the sheer creative brilliance of the concepts presented is hard to deny, and yet in the final analysis the books are merely okay, not great. Along with Mieville and perhaps John Courtenay Grimwood, you could put him into the category of authors who should really be designing RPG settings rather than writing novels... if only there was enough of a market and enough money to support that.
My favourite Barker idea is Abarat - a fantasy archipelago in which each island corresponds to a different hour of the day, where time never changes. The first island, corresponding to 1am, is the "Pyramids of Xuxux", where six pyramids rise up out of the sea; at 9am is "Qualm Hah", which is divided into two halves, one densely populated and the other empty; at 3pm is "The Nonce", an island of rainforests which induces immediately sleep in visitors. As you can probably already tell, Barker demonstrates in it a genius for names - other islands are entitled Yzil, Hobarookus, Yebba Dim Day and Ninnyhammer.
At the back of the first book is an appendix containing Klepp's Almanack, in which Samuel Klepp, a famous traveller, details his journeys through the archipelago. For Yoon-suin I'd already planned on having a similar device in the form of Laxmi Ghuptra Dahl, but flicking through Klepp's almanack has confirmed it in my mind. All fantasy campaign settings should have travelogues, I feel, if for no other reason than to give the DM and players an idea of what the world is like at the level of an individual adventurer. Thinking back over the D&D campaign settings I don't think any of them used such a device, which could be one of the reasons why I always felt them to be in the most part flat and lifeless.