When you search your bookmarks on del.icio.us, all you are searching is the tags, titles, and descriptions. If you want to search the full text of the underlying bookmarked pages themselves, you have to go to Del.izzy, a site out of Melbourne, Australia that was hacked together in three days. Del.izzy takes each page that you’ve bookmarked and puts it through a Google custom search to bring back results for the search terms you enter.

It is a pretty obvious feature, and there is no reason why del.icio.us, which is owned by Yahoo, can’t do this itself. And perhaps it was simply a design decision. You could argue that searching only through tags, titles, and descriptions returns better results because all of the words in those elements are essentially explicit, higher-level categorizations of the content being bookmarked. And the nice thing about searching on del.cio.us is that you can get results for everyone’s bookmarks, not just your own.

But by searching the actual text of the pages themselves, you can catch keywords that were not captured elsewhere. And in this case, more results are better, because any one person’s set of bookmarks is going to be a relatively limited set of pages.

The problem with Del.izzy is that it doesn’t search the tags, titles, or descriptions. It only searches the text of the underlying pages. What you want is a bookmark search that does both.

A search for “video advertising,” for instance, turned up the same top result, but the rest were all different (see screen shots below). Are the Del.izzy results better? Not really. But they show you what you is missing from a standard del.icio.us search.