Being an idiot, I clicked on the up2date icon that appears in the bottom right corner of the screen next to the time in GNOME environment, and clicked on 'Remove from this panel'. It's the small icon that was sometimes red in colour and other times green, depending on whether there were updates or not.

I would like to get it back there if possible but don't know where it is.
Thanks

/etc/sysconfig/rhn/*

Look for something called Red Hat Network or similar in the menu and open it. I think it will start showing up in the taskbar after that.

I have tried adding it to the panel from the menu. It puts a big green circle icon there, which is double the size it used to be. It also doesn't do anything when I click on it. I have no internet on linux at the moment, can't get my wireless card to work, but before when I didn't have the internet, it would at least come up with an error saying it can't connect to up2date, now it does absolutely nothing and it's not the right icon size either! Never mind, until I get the wireless card working, it's not really too much of a problem since I can't update anyway.

you could also reinstall it .... i mean up2date not all the os :-)