Mod Spotlight: ImmersiveHUD
This mod will hide a lot of the HUD elements when you don’t need them, such as outside of combat, with the goal being to create a more immersive experience with the less amount of UI clutter as possible.
“The mod is created with questing in mind, and is not tested in dungeons at all. This mod is not done and still needs a lot of work, but should be ready for testing anyway so if you find a bug or have suggestions please let me know. Next on the to do list is a options panel and adding more HUD elements to show up when moving the mouse cursor to the bottom center of the screen (this currently only brings up the ability bar).”
More information in the original thread here. The mod can also be downloaded there.