Click to select from a list of tags in jQuery

I'm struggling to find a tag selection UI for a rails app. Ideally it would be something like the selection here on Stackov开发者_运维问答erflow, or on Delicious or Digg.

I want users to be able to select multiple tags with a single click. We're already using jQuery, so it makes sense to use something that takes advantage of that. I've used the selection ui in jQuery and I'm not thrilled about having users need to hold down ctrl to select multiple tags.

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I've used the jQuery tokenizing autocomplete to great effect:

http://loopj.com/2009/04/25/jquery-plugin-tokenizing-autocomplete-text-entry/

It takes valid JSON from the server, which is a piece of cake in Rails!