Bulky Crochet blanket - thinking this will be a nice winter time project. Per another pinner's comments: Rows of half-double crochet done in the back loops only, using bulky (weight class or super-bulky (weight class yarn with a P or even Q size hook.
Grietjekarwietje: Het netjes afwerken van je haakwerk - This is a cool way to do an invisible join. The page is in Dutch, but can be translated by clicking an icon to the right. There are also photos which clearly show the technique.