I think the secret to getting widespread publicity is to build something that people want and are eagerly awaiting. I wrote "Write yourself a Scheme..." because I'd seen complaint after complaint about how there were no Haskell tutorials that build a practical project or deal with IO, so I started with some practical IO in the first chapter. When the tutorial appeared, it merely fulfilled a niche that everyone wanted to be filled.
FictionAlley was the same way, though I wasn't around for its birth. Basically, everyone was complaining about how Fanfiction.net sucked and the servers were always down and they eliminated the forums and arbitrarily removed stories. So eventually, some of the leading members of the HP fandom said "Well, let's start our own site then." And since everyone was already dissatisfied with FF.net, it spread easily through word-of-mouth.
1. Your example is _extremely_ specific, and so will match up closely with the needs a particular (small) percentage of people. A news aggregator is very general. The whole reddit audience could shift to klipboardz tomorrow with little effect. That "little effect" is actually a bad thing. Little bad effect, but also little good effect.
2. Your example is a document, and not a service. In short: There are many, many more websites that make it to the top of reddit or digg, than there are reddits or diggs.
_Its a new site that will allow you to keep all of your day to day information online, so you can access it anywhere._
Just some honest advice here, coz' I'd hate to see somebody spend months and months to do something so unspecific and, well, done-to-death.
Did you notice that news.yc became reasonably popular almost the second that it started? Well, Paul Graham has a built-in audience, and that's how it happened. reddit is popular for a similar reason: Both pg and Joel Spolsky gave it some promotion. So, you know, you can't expect a similar trajectory.