How to get your missing scroll bars back

Notice anything funny lately about scrolling on your Mac? (That is, besides the fact that scrolling on your mouse or keypad has been essentially reversed by default.)
Look carefully at the browser window on your desktop—and specifically, look at the right side of the window. Um, where are the scroll bars?
No, you’re not seeing things (or rather, you’re not not seeing things). Along with other changes borrowed from the iPhone and iPad, Mac OS X “Lion” (a major Mac system software update that was released in 2011) has adopted the barely-there scroll bars in Apple’s ubiquitous mobile devices.

In earlier versions of Mac OS X, prominent scroll bars were present at all times—handy for letting you know where you were in a lengthy web page, or for simply letting you know that there’s hidden content either above or below.

Just select "Always" in the General preferences pane to get your scroll bars back.

In Lion, however, the scroll bars are thinner and lighter than ever—and in some cases, they may completely disappear when you’re not actively scrolling.

While Lion’s no-scroll bar aesthetic might be daring from a design perspective, it’s a bit disorienting for the rest of us. Luckily, it’s easy to get those scroll bars back—not the old, larger versions, mind you, but at least you can keep Lion’s skinny-mini scroll bars visible at all times.
Here’s how:

Click the Apple menu at the top-left of the screen, then select System Preferences.
Next, select the General preferences pane; it’s the very first one, up at the top.
Under the “Show scroll bars” heading, you’ll find three options: “Automatically based on input device,” “When scrolling,” and “Always.”
Go ahead and select that last “Always” option. You’re done!