You can use a short length of PVC mounted to the wall (perhaps behind or beside your entertainment center or desk) as a place to tuck all your extra cords. They'll fit inside and instantly "tidy" up ...

Make an improvised guide by screwing together scraps of 2×4. Saw using a handsaw with a blade that’s 3 or 4 inches wide. Note: Square pipe ends fit snugly into the fittings, allowing plenty of contact ...