[centerwaters]

are there any really cool apps that can show off my Galaxy Nexus?

[mr.wizard]

Use face unlock..you use your face to unlock the phone. That's pretty cool

[yosteve]

I upload movies to my phone and show them in portrait. The Matrix is my favorite.

[pool_shark]

It depends on your intended audience.
Movies of course look great.
You can use skiftka to play music via another device like the PS3.

If your audience is a tech geek and you're rooted, you can show them a terminal emulator with busybox running Unix commands.
I just wrote a script to show my cpu performance separated by cpu0 and cpu1.

[bakerbert]

Google Wallet.....I have yet to find anyone that is not impressed when i make a purchase, just by touching my phone to a little pad.

Some cashiers did not believe it was real and wanted to know how i did it.

[Joeyosaurus]

My coworkers and I have been using beam to share some media files and a few apks.

Not too sure how unique beam is to the nexus, but it's still pretty neat.

The rapid fire shutter speed is usually pretty impressive to show off as well.

Sent from my Galaxy Nexus