JavaScript project ideas

I'm going to keep an ongoing list of practical JavaScript project ideas since this was a highly requested topic.

The list below is organized by category. I'll keep updating it, so feel free to check back from time to time.

UI stuff

  • Autocorrecting text box
  • Form validator
  • Collapsible navigation menu
  • Countdown clock
  • Modal dialog box
  • A site that lets people design their own UI elements (buttons, mastheads, etc.)
  • Customize greeting if people came from a certain site

E-commerce

  • Price estimator
  • Front end of an interactive online store
  • Shopping cart front end

Finance

  • Tip calculator
  • Cost splitter
  • Investment calculator
  • House or car payment calculator
  • Savings calculator

Tools and utilities

  • Page that grabs data from somewhere on the web and puts it in a useful format
  • Random name picker
  • Unit conversion calculator
  • Secret message encoder/decoder

Fun and games

  • Basic quiz
  • Rock-paper-scissors game
  • Pong game
  • Madlibs
  • A mario-style game
  • A zelda-style game (more likely a 2d one until 3d performance improves on the web)

Social applications

  • Social network front end
  • Real time chat app (using socket io)

API stuff

  • Gif search, video search, etc
  • Something with maps (like a store locator)
  • Something with geolocation (e.g.: find XYZ near you)
  • Real-time feed of tweets about a subject of your choice
  • Text-to-speech
  • Combinations of any of the above

Console tricks

  • Scrape a page through your console and get info easily without having to copy, paste, and format each thing by hand (great for research)
  • Change colors of your favorite sites to see what they'd look like