I wasn't aware that you could just submit your url to digg. I have submitted articles - is there a separate procedure for links?
Submit your website to Google so that the bot can crawl your website : http://www.google.com/addurl/?continue=/addurl After, build quality back links pointing to your website,
Best way to get indexed quickly is to submit your sites rss feed to an aggregator like Feedage.com and then submit your site to Digg.com. I created a site on Friday night and it was indexed late Sunday with this method, in less than 48 hours. Additionally I created a site on Saturday night but didn't submit any rss feeds or to digg.com and it still hasn't been indexed, so these techniques definitely work.
Add to Google webmaster tools and as mentioned before add enormous amounts of backlinks. To find out how read some articles on this issue and you will find alot of useful information.