Create your own light installation! The Hayward Gallery is hosting Dan Flavin: A Retrospective (this seems to be the one that was at Chicago’s MCA recently) and has a fun interactive site to go along with it. You can create your own light installation dedications and add them to the pool. You can view other people’s here.
If you send yourself a copy of the image you create then you’ll have a URL to it like the one for the image above. Feel free to post a link to your creations in the comments.