Hi Darren,
I wouldn't mind doing articles like this too as it actually ties in with something on my ToDo list. All I'd want in return is the credit for having written it and a link back to one of my websites. I think that's the standard deal.
If that sounds okay, give me a topic and I'm away!
One question, would it have to be text only or would screenshots be appropriate? I could probably do a couple of Flash tutorials too given enough time. A month maybe.
Interestingly, I have some software being worked on now that might be of interest to your clients. So get in touch either way.
Cheers,
Frank.