I think its funny how many people want to learn how to make a lightsaber or build one from scratch. My answer to that would be how real do you want the lightsaber to be? If you want it to be like the ones you can buy which are listed below, then its definitely possible.

Star Wars Yoda Force FX Lightsaber EP3 MR Sealed

US $70.67 (8 Bids) End Date: Saturday Nov-22-2008 9:18:24 PST Bid now | Add to watch list

Star Wars Force FX Lightsaber Construction Set

US $82.99 (0 Bid) End Date: Saturday Nov-22-2008 9:27:06 PST Bid now | Add to watch list

But if you think you can build real ones on your own that actually have a plasma type light come out of a small handle, then you are living in a dreamworld. If such a thing existed it would not be so easy to build, and not so cheap to make it either. So lets just stick with what we can get thats out now, cause thats the best most of us will probably be able to afford.

Green Light Saber Sword Star Wars/LEGO - Nintendo Wii

US $13.96 (0 Bid) End Date: Saturday Nov-22-2008 8:57:34 PST Buy It Now for only: US $13.97 Bid now | Buy it now | Add to watch list

Blue Light Saber Sword Star Wars/LEGO for Nintendo Wii

US $13.96 (2 Bids) End Date: Saturday Nov-22-2008 8:57:38 PST Bid now | Add to watch list

Red Light Saber Sword Star Wars/LEGO For Nintendo Wii

US $13.96 (0 Bid) End Date: Saturday Nov-22-2008 8:57:46 PST Buy It Now for only: US $13.97 Bid now | Buy it now | Add to watch list

1977 Star Wars Darth Vader Figure With Light Saber

US $9.99 (0 Bid) End Date: Saturday Nov-22-2008 9:00:00 PST Bid now | Add to watch list

Master Replicas Qui-Gon Jinn.45 Scaled Lightsaber RARE

US $249.99 End Date: Saturday Nov-22-2008 9:00:32 PST Buy It Now for only: US $249.99 Buy it now | Add to watch list