UFO4 was officially released on October 15 though it took a few days for it to post to all the e-book stores. If you haven’t purchased your copy yet, here is where you can find it:
Direct from UFO Publishing (Paperback)
Direct from UFO Publishing (E-book)
Barnes & Noble
You can also find UFO4 on GoodReads (not a sales site, just for reviews/catalog purposes.)
There have been two reviews that I know of so far — read them at Tangent Online and Amazing Stories.
We’ll give away some copies at SF Signal and Goodreads next week — I’ll post those details once the giveaways are live.