Accessible slider:
http://www.filamentgroup.com/lab/…


Coda Popup Bubbles:
http://jqueryfordesigners.com/coda-popup-bubbles/

Charts using canvas and jQuery:
http://www.filamentgroup.com/lab/…

Flexgrid:
http://webplicity.net/flexigrid/

Check out these posts too:

  1. Create a one-time popup using jQuery
  2. jQuery API
  3. Even more jQuery samples
  4. Easy Drag and Drop with jQuery
  5. Masked Input plugin for jQuery
  6. Advanced Event Timeline With PHP, CSS & jQuery
  7. jQuery Plugin Repository