Lack of ideas

[Johannes Thorén]

I've got a problem. Since i got a lack of imagination, i need help to generate some ideas of what programs i should make
for my java exam.

I have to make 7 programs untill thursday.

4 programs should be made to show that i know how to define objects of my own and use them in different ways,
use object with references to vectors and other objects. And have to include inner classes.

3 programs have to show that i know how to handle IO, standard input and standard output
files, textfiles and binary files.

If you have any idea of what i could make, please tell me.
Since i only got 6 days, it cant be to big programs.