I have two. One is a floor standing with an adjustable goose neck. I love this, and won't sew much without it.
I have a table top sized one that have on a shelf over my sewing table, and it really helps when auditioning fabrics. I usually like my choices when I have used the ott light than when I have depended on the regular light (ceiling light).
I am glad I have them. I bought the floor one at JoAnn's when it was on sale, and the other was from a LQS. But a joyce888 said there are other places that sell them. My local Michael's sells them, but in limited sizes. It may not be Ott brand, but there are "daylight" lamps at most stores.
Some hardware stores sell the "daylight" bulbs that you could put into any lamp.