macosmenu barscreen-lock
Once I've upgraded to Lion I had a new icon on my Menu Bar next to Spotlight. It was an outline of a mugshot similar like one of the Guest account.
When I clicked on that icon I was able to select "Login Window…" which basically locked my Mac.
For some reason this icon is gone. I don't use it frequently so I can't clearly say when it went missing but I'd say within last 10 days probably.
How do I get it back? I have no idea where to re-enable it.
Snow Leopard had a funny way of arranging and organizing Finder views. But we got used to them; however, that doesn't mean they were even remotely intuitive. Lion builds on this confusing and awkward system, changing things up again.
You can see in the image above that there are now two separate options that pertain to the Finder view settings:
The first applies to the current directory (in this case my Downloads folder will always present my icons in Icon View, at a size of 48x48, etc.), while the second applies to all child (or sub-) folders. However, and this is what most people are stumbling over, the "Browse in ... view" is overridden by that folders "Always open in ... view."
Let's run through an example:
You have a folder called Downloads. And in that folder you have another folder called PDFs. You apply both of the above settings to Downloads folder. Now you open the PDFs folder and apple "Always open in list view." You close Finder and open a new window. Navigating to your Downloads folder, will show all its contents as icons, while navigating to the PDFs folder, will show a list view. So now you have the parent folder (Downloads) with both settings enabled, but when you open the child folder (PDFs), it opens in list view.
If you understand the behaviour, it makes sense, but if it's lost on you (trust me, it is on a lot of users as it is far from being an intuitive system), then you'd be scratching your head why both the options are checked, but PDFs opens in list view.
The Guest account is enabled in Lion and ML for the Find my Mac feature as it enables the location function for the Find My Mac feature to work. Without the guest account, the location feature will not turn on and therefore will not work.
Disabling the Guest account will effectively disable usage of the Find My Mac feature.
Best Answer
It can be enabled via System Preferences > Users & Groups > [Unlock] > Login Options > Show fast user switching menu as...