|Kindle (.mobi for Kindle devices and Kindle apps)||Download|
|Epub (Apple iPad/iBooks, Nook, Sony Reader, Kobo, and most e-reading apps including Stanza, Aldiko, Adobe Digital Editions, others)||Download|
|LRF (Use only for older model Sony Readers that don't support .epub)||Download|
They say the catalogue ships at the end of the week but I don't know how long it takes for the files to appear on the relevant web sites. If anybody sees the book on any of these sites I'd be interested to hear about it.
One final note although Smashwords sell books formatted for the Kindle they don't actually distribute to Amazon yet. Apparently that may be on the way soon. I'm told it's something to do with them having an ability to upload the files to Amazon so it's a technical matter. Until that is sorted out Kindle readers can buy the Kindle version of the Hidden Masters from other sellers and direct from Smashwords themselves.