Over past few weeks, Goolge've enabled PubSubHubbub protocol for many Google services, including FeedBurner, Reader shared items, and Blogger. Google’ve now added PubSubHubbub support to Google Alerts. This gives developers the means to write web applications that process newly relevant search results as they become available. Think of it as an AJAX search API that tells *you* when it finds new results. Acting upon these notifications your app could update your website, email friends, send an SMS-- the possibilities are endless.