It is a right of passage of all Jedi to construct their own unique lightsabers, but have you noticed most LEGO lightsabers look the same. It's also frustrating when you show up to throw down with a Sith Lord and you've got a pesky bubble in your blade. Embarrassing!
Never fear Padawan, there are two new custom retailers ready to help you with these shortcomings. The first is eBay seller custombrickz. They often have these lots of 10 transparent colored bars with no air bubbles! I've not bought from this individual before, but they appear to have a strong feedback rating. If interested, check them out on eBay.
The second retailer has just recently debuted on BrickLink. The store name, The Butchered Brick, may be new, but its proprietor is not. eclipseGrafx has opened his store largely featuring custom lightsaber designs and other assorted accessories.
Between these two, your LEGO Jedi can not only fight with honor but also in style.
(Thanks to Daniel R. for the heads up on "custombrickz". "The Butchered Brick" found via eclipseGrafx's Flickr stream)