click here and you get a little box. What more do you want?
Why don't you suggest a laptop to your dad?
The problem is still that small is going to be expensive. There are some components that you can only make so small, without paying a massive premium. Remember that if you buy a small box now you will really strugle to upgrade it.
There are some suppliers who do all in one units (similar to the MAC design) where the components are either in the keyboard or on the back of the screen.
There isn't really the demend for a really compact box in the mass market. When people want them in the lounge, kitchen, garage then thing may change.