I like the sentiment behind this build by Ikea hacker mcquarris. Using a bunch of leftover parts from previous furniture acquisitions, they cobbled together this garbage can mount to hide a trash can under their sink, complete with lid that lifts when you open the cupboard. It reminds me of some contraptions I made when I was a kid, except with much better style. Well done!
Auto-opening trash can made from Ikea junk