Couches are blocks that you can place down and sit on, just like Chairs. However, unlike Chairs, when you place couches next to each other they will change appearance and "attach" to the other block, no matter what color. Couches that are any length of blocks, as well as a couch along a corner (inner) can be made in this way (see picture to right). They will stack up to 8 in a slot, just like Chairs.
To sit on a couch, simply right-click on the block with an empty hand. To get up, press Left Shift.
Their texture is that of wool, which is sampled from the current texture pack, so they will be supported no matter what texture pack you use.
Crafting Recipe Edit
Pre Kitchen Update:
Couches were only available in 5 colors. They could be crafted with 6 of the corresponding wool color. The colours available were red, white, black, green and brown.
Post Kitchen Update:
Couches are now made out of White Wool only, and are now dye-able to any colour! Just hold your dye and right click and done!