How do I set custom search engines in Android? For years now, on every browser I own, Firefox, Opera, Chrome and Internet Explorer, I've assigned w as a shortcut/keyword to the custom search engine http://www.google.com/search?q=site:wikipedia.org+%s&amp;btnI.  That is, I just type w android comparison to jump to the befitting wikipedia article.  I use many, many other custom searches.

Is there a way to set this up on Android?  Not necessarily with the stock browser?
There are a number of apps that will either give you a Wikipedia search widget on the home screen, or add Wikipedia as an option to the built-in search widget's drop-down selection. Have a look at a few of these: https://market.android.com/search?q=wikipedia+search