Thanks for the suggestions. I use the Google Toolbar to search the current site. What would be nice is to be able to search a bunch of related sites at the same time. You can do through various web sites. You have to set up a group of sites that you want to search i.e. create your own search enging e.g. http://www.google.com/cse/. I thought it would be a lot more convenient if you could somehow do it through Diigo. Oh well.