We used this to automate UI tests on an iOS app a couple of years ago (before they added the UI automation stuff). Seemed to work pretty well, though it was a fair bit of work to get it set up.
i made a fishing bot for wow using sikuli a while back - it was rudimentary but since fishing in wow is mostly just clicking the bobber, it worked pretty well. i'd let it go overnight and would wake up to bags full of fish every morning.
Sikuli is great. We use it to click on the "Sync Branch" button on GitHub app window every minute on our dashboard screen. Seeing a live stream of commits is very motivational.
The only problem is that the Sikuli scripts can stop working easily when you resize the window or restart the computer. Something changes on the screenshot so it stops finding the button.
I recall trying to use this in 2003 to automatically click on some car website to collect points so I could get a free flatscreen TV.
I ended up using AppleScript when Sikuli didn't work to automatically click the mouse every X number of seconds and only ended up with a free T-shirt. :(
+1. Sikuli was a dream find a few months ago when I had to upload 100s of images for a rater survey to a locked-down LimeSurvey instance (no ftp allowed). 20 minutes and I had a functioning script that pushed all of the upload buttons and paste the next filename in sequence.
