Great Concept Rated 5 out of 5 stars
It does exactly what the developer says that it does and I like the idea of this add-on, but I currently have 20 search plugins installed and some are very site and/or content specific and not general such as Google etc so running a search through all search plugins is just too much for me personally.
What would make this an awesome and very useful add-on is the ability to create sets of search plugins to use so for example, I could run a search on a particular phrase using a customized set of search plugins such as Google, Wikipedia, Answers.com etc and name the set General etc.
I could also create a set named Mozilla that contained search plugins for Mozilla Developer Center, mozillaZine Knowledge Base, Mozilla.org and so on.
I could just as easily use Google Co-Op but this add-on would allow me to get results for each site individually. Adding a toolbar button would also be great.
Thanks for developing this. I hope that you can and do implement the search sets idea.