how to make a lightsaber blade?

I have one for trade with a partially painted obi wan statue here https://www.facebook.com/photo.php?fbid ... =3&theater

Blue transparent plastic is obviously ideal, but if you have some transparent blue paint, you could apply that to a colorless transparent plastic rod for the same effect. You could potentially use the transparent ink "stem" from a pen, which are usually clear, and put transparent blue paint on that.

If you can't find any cocktail stirrers, like Darththomas suggested, you might try hitting up your local thrift stores and rooting around, you might find something that you could use for cheap. For example, I found a Playskool Darth Vader this past Saturday, for twenty-five cents. While his saber is the wrong color (red), it was transparent.

Cocktail stirrers come in a variety of colours dude.