Will HDMI cables help with delay (lag) on my HDTV when i play Halo on my XBox?

I have a Vizio with 720p capabilities. The lag is nothing noticeable to the relaxed player, but i have been whining about it ever since i got the new tv, upon returning home for the break i connected my box to a standard tv and was dominant all month long, because there was no longer any delay. Will HDMI cables solve my woes or will they simply make my the picture of my dead body prettier and clearer?