This is an interesting debate because one could argue that if your content is valuable to the community, then it's worth posting to Digg / Reddit / Del.icio.us before anyone else does.
However, the counter-argument is that cream rises to the top, and that the crowd will and should determine the value of your content. The problem here is that the sites above are still primarily used by the geek audience, which is far less patient than your average internet user.
Personally, I say go with what makes you feel comfortable, but always ask the question "Will other people find this of use?" and/or "Why should other people read this?".