The JBL WEM-1 Wireless Expansion Module promises to extend your speakers wirelessly up to 70 feet. You hook one module up to your A/V receiver and then you hook your speakers into the amplifier module. The price is a bit steep in my opinion ($359 currently $253 on Amazon), but the concept helps cut down on cable clutter while extending your speakers’ reach.
When it comes to wireless speakers, the quality is not quite there and the offerings are few and far between. Even this JBL offering only offers up 50 watts per channel, but this is a decent step in the right direction.