Well, the question you ask above, is not one that has a simple yes or no answer.
One of the core ideas underneath EVERY Linux distribution, is the hierarchy of users with varying levels of privilege. Root is the most powerful user, who can do anything, including destroy the installed system. For this reason, it is not generally accepted practice to give ALL users the same amount of access privilege, otherwise, ANY user could theoretically bork a system really badly.
Most of the stuff on a Linux system is READABLE by regular users, but not WRITEABLE. And, some folders are not even ENTERABLE by a regular user, only root.
Now, you're using Ubuntu, which has even MORE restrictive measures in place: the root account is not even fully enabled, and/or there is no password associated with it, making it very hard for a regular user to damage the system. In the Ubuntu world, you guys use `sudo` to get some limited, temporary root powers.
So, in short, the smart answer is NO, there is no way to allow ALL users to access ALL stuff on the machine freely at will. Letting all users have this sort of access is a bad idea.
Now that we've made that clear, I'll give you another thread to look at, just for another perspective on what you're asking: http://www.linuxquestions.org/questi...om-gui-782655/
And after having read that, if you have further inquirires, feel free to ask! As mentioned in that other thread, I don't use *buntu myself, but loads of users here do, so someone will be able to answer your questions if I cannot.