Hi!
This is my first time posting, so I hope I chose the right forum.

My question is simple, is there any way that I can make my Ubuntu Karmic powered laptop work as a giant USB drive when I connect it to another laptop for example. As a normal usb pen drive works, just plug it in, but now instead, my laptop would act as one.
It would be perfect to have a folder which content would appear on the "virtual" usb drive when connected to something.

I've tried to search for this, but didn't find anything.

Welcome to LQ.

What you want to do is turn your laptop into a file server - which is easier than the letter of what you have asked for. Also more flexible and useful.

rt-click on the folder you want to share, select "sharing options" and follow instructions.

If you only plan to use this with computers that are not on a network, nfs sharing using a crossover ethernet cable will probably work well for you.

There are projects to allow gnu/linux computers to act as UMS devices when plugged into other computers by usb cable. Normally for embedded linux as in phones and pdas. eg.
https://wiki.ubuntu.com/MobileAndEmbedded/USBClient


I don't know of any special headway. linux is just good at server stuff. So if you really want a usb connection to serve files, you are looking for IP over USB.
http://www.linux-usb.org/FAQ.html
http://usbip.sourceforge.net/
http://www.linux-usb.org/usbnet/