For other bills, I got all but one to put me on "budget billing" (same amount each month, so Fidelity just sends them a check for that amount without seeing the bill). For Windstream, which varies by a dollar or two each month, I just send them an amount on the upper end and then let a credit accrue. Both of these require an update maybe once a year or so.
Windstream is a bit funny - I don't know why they can't pick a number and stick to it. Also, they apparently raised my "guaranteed price for life" a couple of times and didn't notify me until ~8 months later when they were threatening to disconnect my service for being more than a month behind. (They had turned off paper billing on my account but didn't actually enable e-billing - service still worked so I didn't even think about it. We eventually got it straightened out, but Windstream is ... special.)
Beyond that, I made a bot that automatically withdrew Elance earnings to my bank account (that got me banned for a week or so when I posted it to their forum).
I made another bot that bought and sold bitcoins and litecoins and such. It was moderately profitable until my exchange (criptsy) got hacked and lost all of my float (worth ~$60 USD at the time.)
I connected an Arduino IR blaster to my TV to make it automatically turn on my sound bar (the TV would turn it off, but not on?!) - http://www.nfriedly.com/techblog/2015/01/samsung-tv-turn-on-...
Oh, and of course, code tests and deployment. Nearly every git commit I make gets a ton of tests, and for most projects, each tag gets an automated deployment to to npm or bluemix or wherever.