Brad,
First I wanted to say "thanks!" for your continued high-level posting. I've learned a lot, and so much more to learn. Through your posts I finally listened to Wolfram speak at MIT yesterday, read Wikipedia articles on a slew of names, and it was all quite enlightening. It's my first step into simple cellular automata and biological math. So THIS is a big part of where you're coming from.
As for the pics, I would keep the BIG size like this, and just resize it using HTML. I assume you know how to do that, since I've read some of your posts around the web. Not that I'm stalking you though haha. Just I understand there's a lot I can learn from you.
Anyway, just for your sake, I'll leave a copy/paste template you can use. Replace the "PIC" with your photo URL in two places. I think that's the best approach. If you don't make the original big size available, those who want to look closer won't be able to read it.
Ben