Kayak.com is a website that allows you to search for airfare and travel needs.
It has an interesting search UI.
Go ahead and do a search for a flight, and you will see that instead of the usual:
“I am searching, be back in a minute”
- I have done x out of y
- Here they are
- Feel free to stop me at any time if you have enough info
- Oh, and I am done now so here is everything
The funky changing display on the left is fun too. This is a lot nicer for me the user. I get feedback at the right time (when available), and I am engaged.