My friend José Miguel Torres has just published a brand new ebook on SQL Server Compact Edition; if you are a guy that is doing mobile devices development this book is a must; unfortunatelly the ebook is only available in Spanish.
This is the reference to the news:
http://geeks.ms/blogs/jmtorres/archive/2008/09/16/sql-server-compact-edition-buenas-pr-225-cticas.aspx
You can by the book from here:
http://www.solidq.com/ib/Press.aspx
By the way, if there are many English speaking developers interested on the book, the editor may consider translated to English... If this is your case, don't hesitate contacting the author.