Antec recently launched their own line of rounded cables, the Antec Cobra Cables. Why did they call it Cobra? Well I guess that they named it Cobra because these cables are very flexible, and their black nylon mesh with red stripes really makes them look a bit like a snake. Why would you need rounded cables you ask? First it looks a lot better than the ugly bulky flat IDE cables, and second it improves the airflow in your case!
Read my review here