I also get a lot of requests for free technical support, mostly because of my involvement with the S3 Savage driver for XFree86. My website is linked from a lot of graphics web sites, and that puts me high on the Google hit list for Savage questions. Many people do not bother to read the part about Linux, so I get a lot of marginally related Windows questions as well.
This month, I had an e-mail exchange go horribly bad. I got a question from a hysterical, hypersensitive, 48-year-old former elementary school teacher who decided to misinterpret my response in the worst possible way. The exchange just got worse with each exchange. It is an excellent example of how e-mail can cause disasters, as well as being a fine case study in the differences in communication styles between men and women.
It makes for an amusing read, as long as you keep saying "thank goodness this didn't happen to me": www.probo.com/timr/Deed.html.