Select Statement Is Very Slow - How Can I Speed This Up?

The following stored procedure is run whenever someone searches my database.  When I first created the site, this search took less than 3 seconds.  Now, there is more data in the system and the search is taking over 30 seconds.

I am not very good with SQL and I'm sure I am doing some dumb things.  Is there a better way to write this query to speed things up?

Thanks a lot,

Chris MessineoSET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:Chris Messineo
-- Create date: 4/27/2007
-- Description:Get Search
-- =============================================
ALTER PROCEDURE [dbo].[Search]
@Keyword as varchar(40)=NULL
AS
BEGIN
SELECT
Script.Title,
Script.ScriptID,
Script.Logline,
Member.Name
FROM
Script
Join Contest on (Script.ContestID=Contest.ContestID)
Join ScriptComment on (Script.ScriptID=ScriptComment.ScriptID)
Join Member on (Script.MemberID=Member.MemberID)
WHERE
(Title like '%' + COALESCE(@Keyword, Title) + '%' or
Logline like '%' + COALESCE(@Keyword, Logline) + '%' or
Comments like '%' + COALESCE(@Keyword, Comments) + '%')
GROUP BY
Script.Title,
Script.ScriptID,
Script.Logline,
Member.Name
ORDER BY
Title
END