OK, so this might be an obvious one for 'Glee' fans, but we can't help but do a double take every time we see Lea Michele and Idina Menzel side by side! Michele and Menzel actually star on 'Glee' together as daughter and mother (respectively), and it's pretty obvious why Ryan Murphy and co. casted Menzel as Michele's onscreen mama.

Although Menzel -- who made a name for herself in Broadway productions like 'Rent' and 'Wicked' -- is 15 years older than Michele, the actresses/singers have incredibly similar facial features and bone structures. We bet it's eery for the starlets to look at one another -- it must be like a time warp for both of them!