I like the new Google Search widget (currently only available via http://draft.blogger.com). Unlike the Google Custom Search, which has been available for awhile, this widget puts the results into your site, instead of sending visitors offsite. You can add the widget to your existing blogger based blog, (i.e., you don't have to have a 2nd "draft" version running). The widget takes up a little bit of sidebar real estate, as shown here;
Once a search is complete you'll see the results displayed in the main section of your Blogger blog, above the latest posting;
You can also select from different options to show results from the five categories (listed above).