You can do that setting up the vocabulary (or container if you use Category module) as "freetagging".

Users will be able to input more terms at once dividing them with a comma, and also to see which terms already exhist thanks to AJAX autocompleting.

Marco

On 28/feb/07, at 2:02 PM, Mattias Hällkvist wrote:

Can you let users input several taxonomy terms for one category in just one input form?

Cheers! /Mattias -- [ Drupal support list | http://lists.drupal.org/ ]