Todd Coram: This Wiki is a very rich resource. Browsing is nice, but I kinda wish that the gems here were available in printed format. Not exactly a cookbook, but an edited best of Wiki (games, toys, techniques, hacks, etc).
RS: This topic has been discussed several times in the Tcl chatroom. The biggest problem seems to be the very different views on copyright by publishers and by us. A publisher would require to receive the rights to the text of the book, and might even sue people who reuse contents of this Wiki. (I think it happened to Wolfram's MathWorld). So for the time being, even if we found a willing publisher, chances are very little... Actually, the title for the non-existing book that I had in mind is "Arts and crafts of Tcl-Tk programming" ;-)
Todd Coram: Ugh. Darn publishers. I suppose it would depend on the publisher. I did a chapter for an Addison Wesley book and retained full copyright on the text. But, I suppose a Tcl Wiki book probably wouldn't sell big, so the publishers would try to get every dime (and rights) possible. I suppose it would be pointless to do an online book (since the Wiki is *online*). Although such a book would be targetted toward printing (PDF or postscript).... sigh, just thinkin'.
RS: Actually my daughters at times nag me to write a book on Tcl (so they share some of the fame;-). Of course lots of Wiki content could be reused for that, but must be a rewrite from scratch (to be decoupled copyright-wise), and would take some time accordingly. If anybody knows a daring publisher, drop me a note!
CJU: Doesn't O'Reilly have several books that are available in both hardcopy and freely-distributable electronic form?
kroc: You might publish yourself your book with Infinity Publishing
SS: lulu is another print on demand service that may allow to actually create such a book
MAK: There is also CafePress .
James: You might want to try BookVenture Publishing
CL can help with print-on-demand planning, and generally wants to encourage anyone with the right heart to regard copyright and other business distractions as solvable problems.
Larry Smith: I think any of the print-on-demand services would happy to do the job, they don't require you to sign over copyright. As far as they are concerned, you own the copyright. If you represent a bunch of authors who have all agreed to a certain license - as in the wiki - it's all the same to them.
On the subject of the book itself, if it is truly meant to provide structure to a subset of the wiki pages, rather than using them directly and editing them at all, then the book could be structured as a wiki page itself, with appropriate links to the relevant articles. That way, it automatically updates whenever an included page is edited. I can even see a "reference shelf" of such volumes on different topics pointing to various subsets of wiki pages. If the book itself is, in fact, merely a snapshot of a current set of wiki pages, copyright shouldn't ever even enter into it.