I wrote some technical articles for a variety of publications, one of them paid me about $5,000.
(Plus my salary and bonuses went up a LOT because of doing this because I was a consultant specializing in what I wrote about.)
Thanks for this idea...my company's been pestering us to write/publish more, and I didn't see any potential upside for the time involved until you mentioned this!
My salary went up $10,000 a year when I sent the book of to the publisher and another $10,000 when it was put in the hands of the company owner. The salespeople loved it because they could say "Our guy wrote the book on this software!"
If I had a regular corporate programmer gig that would not have happened. But because that book drove consulting sales it sure did.
I could take a variation on the article and present it as a paper at a technical conference. Presenting often meant I did not have to pay to attend the conference. (Still cost travel and expenses, but it made it a lot more likely that my employer would send me. Even when I was just a corporate programmer...) As a consultant I made a point of collecting business cards of likely prospects for our services and getting them in the hands of the sales people. That made them more willing to send me to more conferences... Plus, of course, that mean I was also getting lots more training than most people were, so even more raises...
Didn't get to go to one annual conference that I usually went to because a consulting gig was in the way. My boss went. People saw his name tag with the company name on it and they all asked him where I was. I got a big raise after not going to that conference because he realized how effectively I had branded the company as experts in my field. :)
I would get extra billing hours by volunteering to write up a detailed how-to on a time-saving utility program I put together for them. A common response was, "You would do that for us?", said in an awe-inspired way. Then I would re-package the documentation as an article or conference paper if it could be used to illustrate something useful. I even got to bill two different customers for writing the same utility that both of them needed. I only worked 40 hours that week but got to bill for 56 because I got to double-bill 16 of those hours. That made me popular with the boss.
Sometimes I would get cash payments, other times I got contacts or reputation that I could parlay into something useful later.
Hope that helps and sorry I didn't see your comment sooner!