one way is to update your content and submit it to digg. then digg will leads google to crawl ur site
post a content daily.... Google will not just crawl your blog daily but hourly... This happen to my blog....
the more you update the content..the better your chances of getting the updates..link building, as realistic mentioned, is also a good way..
social book marking web sites are good way to invite crawlers as well as visitors so start social book marking on digg.
You should have daily updates to your site. Or at least the home page. Probably a blog or a news section. Then you can set the Craw Rate to Higher from your google webmaster account.
Are you talking about Google Alerts? http://www.google.com/alerts You can sign up and enter your website and choose, daily, weekly, etc updates