Here you can find him talking to the AUM Conference in 1973, at Esalen, introduced by John Lilly.
You can easily Google plenty of interesting and interactive sites based on The Laws of Form - we have offered links to them in the past, e.g. The Markable Mark, which has practical tools to play with.
It can prove hard to find copies of the more poetic books he wrote under the name James Keys: i.e Only Two Can Play This Game [Julian Press, 1972], 23 Degrees of Paradise [Cat Books, 1970], etc) but they seem like a necessary compliment to his more technical work.
Wiki lists him as a polymath: "He describes himself as a "mathematician, consulting engineer, psychologist, educational consultant and practitioner, consulting psychotherapist, author, and poet."
Personally, I would love to find out more about his interactions with R.D.Laing.
Still, this remains a birthday greeting, and not a definitive site of cross-references.
For RAW fans, of course, you may recognise an assortment of chapter sub-headings and references cut up into the Schrodinger's Cat trilogy... "That which is not allowed is forbidden", etc.
LIVING IN A NOVEL
Let there be a form distinct from the form.
G. Spencer-Brown, Laws of Form
"Choronzon" was a mindconstruct of the primates specializing in the Enochian version of Cabalistic magick. Talking out of two sides of their mouths at once, as was typical of primate mystics, the Cabalists said that Choronzon was the astral embodiment of all the illusions and deception on Terra (especially all the egotism and malice). They added that Choronzon was also a part of the psyche of the student which had to be faced and conquered before Illumination was complete. When asked whether Choronzon was then outside or inside, they usually answered "Both." This reply made no sense at all until G. Spencer Brown published his Laws of Form.
He exhaled a fog of cannabis molecules and returned his attention to his favorite
bedtime reading, Brown's Laws of Form:
To cross again is not to cross
The opening line of LOF is "The theme of this book is that a universe comes into being when a space is severed or cut apart" .
You may find parallels in Zen Buddhism, in relation to the idea of the Mutual Arising of Opposites:
When you cling to a hairbreadth of distinction,
heaven and earth are set apart.
If you want to realize the truth,
don’t be for or against.
There are other translations of this idea from the Xinxin Ming...
See also: Sanskrit - Pratītyasamutpāda
A useful reference site on Observer Web
Good summary of LOF in Wikipedia
Cuttingup Space, Part 2: The Laws of Form on the Particulations blog
A design for an experimental course, with LoF as the focus.