I just got a samsung t260 HDTV/monitor, and have hooked it up to my xbox 360 via a 15 ft hdmi cable. On my first playthrough (after ensuring that the game settings were at 1080p and the monitor aspect ratio and sharpness settings were correct), I noticed a bit of jagged edges to be found and the picture doesn't look too different from my old SDTV.

I know the 360 isn't great at AA, but I'd like to know if there is any way to 'check' or if there are any visual queues to look for to know that I am in fact playing in HD compared to my old SDTV?