Is it possible to obtain a backlit laptop Keyboard replacement for a standard laptop keyboard? like the Dell XPS L502X (Backlight) Keyboard. My computer is not that old but I use it late at night and the backlit keyboard would come in handy. Does anyone know if it is possible to purchase an upgrade for this?

We don't know what make or model your Computer is, but there may be something available from the manufacturer, or available for a like model laptop.

Alternatively, you could purchase a standard backlit keyboard that is typically used with desktop computers. You would just plug it into a spare USB port (if you have a spare port?) and your laptop wouldn't mind at all. Many people do this.

I'd say probably not. If the PC didn't come with a backlight, it probably isn't an upgrade. The backlight has to be controlled via keybard for brightness, the PC has to be able to interpret the command and adjust power, etc....

The external KBD is the way to go here.