There are lots of English idioms that use body parts like hand, foot, neck and so on. The example in the title is "all ears" which means to give someone your full attention.

Let's check my top ten body part idioms:

1. To give someone a hand (with something)
to help someone
e.g. Can you give me a hand with the laundry?

2. To cost an arm and a leg
to be really expensive
e.g. Is that a Louis Vuitton bag? It must've cost an arm and a leg!

3. Off the top of my head
quick information, without research or checking
e.g. Off the top of my head, I think there were about 20 members in the tennis club.

4. Keep your chin up
try to stay positive in a negative situation
e.g. Keep your chin up! I know the work is hard, but you're almost finished.

5. To pick someone's brain
to talk to someone to get information from them
e.g. I want to buy a reliable car. David is a car mechanic, so I'll pick his brain about which car to buy.

6. To stick (one's) neck out
to take a risk
e.g. I think that company will do well in the stock market, so I'll stick my neck out and buy some shares.

7. To get something off (one's) chest
to talk about or complain about your problems
e.g. Sorry for complaining so much about my boss! I needed to get it off my chest. 

8. (To have a) sweet tooth 
to really like sweet food
e.g. Richard has a sweet tooth, so I'm going to get him some chocolate for his birthday. 

9. To get (one's/a) foot in the door
to enter a company or organisation at a low level, with a chance of becoming more successful.
e.g. An internship can be a good way for students to get their foot in the door in a competitive job market.

10. On the tip of my tongue
to ALMOST be able to remember, but not completely
e.g. Her name was something like Amelia? Alicia? It's on the tip of my tongue but I can't remember. I'll have to check.

So those were my top idioms using body parts. Can you think of any off the top of your head? If you can, I'm all ears!