Where Else Do You Think A Head-Up Display Would Be Useful?

So far, I’ve seen head-up displays on cars and helmets for motorcycles. I haven’t installed any on my vehicles, but I’m planning to get them soon. My friends who own cars with built-in displays say it’s the best feature they’ve seen in new cars in a long time.
It got me thinking that maybe, the device and its augmented reality technology could be useful in many other ways. I chatted with my colleagues one night after work and we brainstormed about it. One suggested to have displays inside really really massive malls so we don’t get lost, while I said we should have head-up displays in grocery push carts! Hey, I have a hard time navigating the aisles, ok?

Any suggestions? In what other places/situations can head-up displays help us become more successful multi-taskers?