>A great place to get a good search script is at >http://worldwidemart.com/scripts/ which is >Matt's Script Archives. I use his simple >search in my site and it works well and >also allows you to omit areas of your site >from the search if you wish.
Matt's search script is precisely the one being used here on this message board (with some customisation).
If you have a lot of pages it can get quite slow (as you'll see if you try searching the archives) but apart from that it's great :-)