I have installed a few modules that I don't use at all. I can't find any option to uninstall them. How do I do it? Is there a separate module to do it?
Not sure about a separate module for this, but you can just delete the module folder in your
sites/all/modules folder. Works for me every time.
The module uninstall page in Drupal 6 is at http://mysite.com/admin/build/modules/uninstall.
For Drupal 7 it's at http://mysite.com/admin/modules/uninstall.
Once you disable a module using the main modules page, visit the uninstall page and you'll be able to safely uninstall. After that it's just a matter of deleting the module folder from your server, and you won't see it in the module list any more.
Whatever you do, don't just delete the module folder without disabling/uninstalling it first, or you could easily wreck the site.
Obviously you're using a drupal version prior to 7.
In this case you can deactivate them in the module list and then just delete them via FTP.
In Drupal7 there's an uninstall tab in the module list...