The prototype and code are in good shape. Knocked out all the bugs I could find, and I've been updating the project page. It's practically a real thing!
Loaded up Fritzing for the first time, and made up a wiring diagram with it. Not very hard to figure out, which was nice. The output certainly looks nice, for the breadboard view.
Once I get a chance to load the latest code onto the processor and see if my latest tweaks have broken anything (hopefully they've knocked down the power consumption a little bit -- 45 mA at rest!), I think this thing is ready to publish.
I still have to put together the encased prototype, but this code is feeling pretty much ready.
Cool new feature idea: adding a temperature probe, and adding a temperature compensation factor per timer: you program the correct time at a given temperature, and a ratio of time change per degree (probably by inputting temps vs. times rather than having to do any calculations on your own) and the timer automatically adjusts time to match temperature. That's for a future version, but I really like it, and it would allow me to stop being so fanatical about chemistry temperature.