I want to buy another Apple machine and instead of buying a whole new laptop, I am thinking of buying just a Mac mini and use my MacBook Pro screen as the screen for it. Is that possible ? What kind of connector would I need ? Would a simple USB cable do ? I am ready to buy a video connector for 30/40 bucks if that will do the job.
This answer only uses the HD of the Mac Mini, while the processor and memory of the Macbook, which is not the definition of "Screen", but you'll be able to use the "content" of the mini.
hope it helps
Depending on what you are trying to accomplish, if you're using simple apps like mail and browsing, VNC (Virtual Network Sharing) might do the trick without any hardware connections. It uses a network connection to stream your screen to a client.
For setting up your Mini as a server and your Macbook as a client, I recommend using this tutorial:
Mac OS X 10.4 or 10.5 - Setup as Server
Mac OS X 10.4 - Setup as Client