He takes old burnt out fluorescent tubes and lights them with regular incandescent light bulbs:
Lengths of 15inchs, 2ft, 3ft, 4ft and 8ft are available. Depending on the model they are capable of hanging horizontally, vertically or free standing. The used florescents are from architecturally significant buildings.
Here is Castor's site: www.castordesign.ca. The effect is really nice, but we also thought this would be a GREAT DIY project as the materials would cost you pennies. Of course, it would take a good bit of work to do as fine a job as Castor, but hey, it can be done.