How to remove comma between taxonomy terms?
Here's a nice blog post on styling taxonomy in node.tpl.php (or node-contenttype.tpl.php): http://oliverdavies.co.uk/blog/how-style-drupal-6s-taxonomy-lists-php-css-and-jquery

Looks like you should check your node.tpl.php for something like &lt;?php if ($terms): ?&gt; and then you might see where the commas are being added and strip them out. This will depend on what theme you are using.