I pretty much am a newbie here and only have two kinda rant diaries to my belt and rather be known for something better. The desire is to contribute something substantive yet something no one else is really doing (I'm kinda sick of seeing 20 of the 30 most recent diaries being of the same 2 or 3 things =P), and for the main considerations a sort of serial diary would work best. There are a couple of somewhat developed ideas but I'd like to throw them out there first to get a feel.
1. Since this has some relevance with our soldiers suffering from PTSD as well as those who have other mental illnesses (many of which are sent into combat duties against their own doctors) I'm considering a series about current issues in mental health. It's something that rings close to home with I'd say a good majority of people in some way (in normal civilian life), and in the vast majority of areas our country has a fairly poor rating in handling it. I also think this can perhaps serve as a humanizing of particular inflictions (I myself am bipolar and would bring that into discussion at relevant points) as well as a PSA. It won't all be doom and gloom, I also consider covering lighter aspects of it (like famous or relevant people here who are afflicted) and perhaps any new findings.
2. I have noticed someone here posting about the EM spectrum and I thought that, as an electrical engineering major myself, I could do a series that's partly a "how things work" type of thing, part demystification of the things we take for granted in life. Possible things I'd consider covering are the basics of supplying and utilizing electric power, particular electronic devices, maybe even giving a general glance of how a computer works. I'd keep the math as low as possible, but will not be afraid to bring in relevant physics as necessary and will try to stick with intuitive explanations as I can.
3. While on the topic of math, I can maybe even do something as an off-shoot that's sort of like "math scientists and engineers use for dummies", in which I'd take a concept I use personally in my work and try to explain it in layman's terms. I already have a fairly intuitive explanation of what the Fourier Transform written elsewhere and ready to go.
Those are my current ones that I'm considering most at the present. I'm going to try and post this in the Open Threads the next few days so let me know if any of the three catch your interest.
Edited to add:
I will link to this diary over the next few days on open threads. Also, I'd like to know if there are any recommended days and/or times to post these things. Not that I'll necessarily follow the advice but for a series-type thing it may be useful to consider.