We have found the Joomla Extension " ReDJ" highly useful, not only for our websites, but for our clients as well.

We had a site that required us to map every page that the client had created in XOOPS, and although we were able to accomodate most page names simply using the 'alias' of an article and menu, this component allowed us to remap the entire site without one broken link.

Pros:

1. Great for a site migration, mapping old links so search engines don't give broken links.
2. Content Updates, you are able to redesign your site, move articles, and no broken links.
3. Frequent software updates. This developer is actively working on this component.
4. Easliy create your own Error Page! No longer do you have to dig through Joomla Code to make changes to the default error page.
5. Free, however they do have a commercial version available if you need extra features.

Cons:

1. Configuration might be a little intimidating because of all the instructions about adding variables, etc.
   (However, you can easily ignore those and not use them.)