How would you create a new language? This guy has given the matter some thought, is deeply interested in language structure, and has included tips and tools for the bold. A large site, and by no means all new, but great fun for word freaks, RPG and SF enthusiasts. He also offers some provocative editorials and reviews.
Strange Visions Plus a New World Order: French comics, anyone? Or Latin American, then? Or consider the real rules of Inglish spelling? Mark Rosenfelder's Metaverse offers many different tidbits, opinions, and -- for me, the crown jewel in a diadem of rare and fascinating pages-- the wealth of information on Vertual Verduria, indepensible for anyone contemplating a venture into world-building.