I've been trying to use an ext3 partition to share files between the distributions on my computer (at the moment CentOS, Debian and Ubuntu), but I'm not quite sure how to allow all users to read and write to the partition. I have tried creating the directory /media/fileshare and adding the following line to /etc/fstab:
in each of the distributions and although this mounts the partition, it doesn't allow ordindary users to write to the partition. I have also tried the options "rw,user" in the place of "default" but still no luck. Any suggestions would be greatly appreciated.

Have you looked at the /etc/exports file on the server? If you export the NFS shares as RO you will not be able to write to them.

I don't want to sound really stupid, but what server?

You just need to change the permissions for the files on the mounted partition. As root:
chmod -R 777 /media/fileshare
Will make the files in /media/fileshare readable and writeable by anyone

You just need to change the permissions. As root do:
chmod -R 777 /media/fileshare
Will make all the files in /media/fileshare readable and writeable by anyone
Edit: Sorry, double-post!

That's great - thanks very much.

Sorry for the confussion, I got your thread mixed up with another dealing with NFS.