Comment IE and Mozilla both have this feature (Score 1) 243
For IE6 you add it to the registry: create a new key under
HKCU\Software\Microsoft\Internet Explorer\SearchUrl
and give it the name of the command (i.e. "g" for google).
Set the default string value under the key to the URL to use; %s gets replaced by what you type after the command. For the google example above, set the value to "http://www.google.com/search?q=%s"
You can also do character->string mappings; create a string value whose name is the character to replace, and whose value is a replacement string. Most common are things like ("&", "%26").
HKCU\Software\Microsoft\Internet Explorer\SearchUrl
and give it the name of the command (i.e. "g" for google).
Set the default string value under the key to the URL to use; %s gets replaced by what you type after the command. For the google example above, set the value to "http://www.google.com/search?q=%s"
You can also do character->string mappings; create a string value whose name is the character to replace, and whose value is a replacement string. Most common are things like ("&", "%26").