While Lion is missing the Save As feature, you can restore it to an extent using custom hot keys.
Potential culprits include WoW.
You can view between one and seven days in the week view of Apple's Calendar application, but this can only be accessed using a hidden hotkey.
If you have an iMac made in mid-2011 or later, here is how you can use it as an external monitor.
If Mail in OS X Mavericks will check your e-mail account only after being launched, then this workaround will help at least check messages until an update is released.
Force-quitting an application can be done directly with one keystroke, if needed.
There are a number of ways to navigate, move files between, and otherwise manage the new Finder tabs in the latest version of OS X.
If you have dragged files to an incorrect location by accident in the OS X Finder, there are several ways to undo this without having to select and drag them all back.
You can fix the inability to move files to the OS X trash by adjusting file permissions settings.
The default content search in OS X can be quickly overridden with name-only search options.