It was excruciating to move around the Rollyo site today, and I couldn't really experiment with what others have done because of poor response time. I almost gave up, but was finally able to create my search roll of catalogs that use Koha software. The search itself was also painfully slow, but did yield results. I'd rather not have results from regular web sites (eBay, Target, OrientalTrading) mixed in when I specify "Koha Catalogs" as the sites to be searched. I'll try searching another day to see if the site is more responsive, and to see if I can fine-tune the search engine to include only the sites I specify.