Harddrive usage

Is there a way (using Lion) to check what applications/folders are taking up the most room on a harddrive?

My wife has a 128GB MBP and after loading Lion it says she only has 3GB of memory left. I do not think it is because of Lion, I am sure it is just a coincidence. But she says she only has a few applications and the same pictures and music she has on her 32GB iPad.

 

Using that it shows that Users occupies 86.1GB. Is that normal? The computer has 1 user and her folder contains all the same things (Pictures, movies, library...)