My street cleaning program appears to be working just fine, except for the fact that for some reason Google never sent me either of my SMS reminders this morning. I looked at the calendar and they're set up and everything; I just never got the message. And it worked perfectly on Monday!
It cost me a $115 ticket for double parking, though thankfully my neighbor alerted me before they could tow my car.
Clearly, I'll need a text-messaging system more robust than reminders in Google calendars. AppEngine will let me set up cron jobs (nullus), which I should then be able to use to trigger a message via Zeep.