There are a lot of places where you can submit blog posts other than Digg and Reddit -- because they aren't as big as the "big guys" you'll usually do much better.
StumbleUpon is amazing for everything - you just have to connect with other users. Can be used *as* a blog.
http://stumbleupon.com
FanPop is a good overall site - but not a lot of people
http://fanpop.com
List of several sites:
http://franticindustries.com/blog/2007/01/22/10-pligg-sites-worth-visiting/
TimeThief in particular might like hugg.com since it is for enviro stuff.
http://www.hugg.com/
here's one for video game development related posts:
http://devbump.com/
Here are a few good ones for programming related posts (secret to my success):
http://programming.reddit.com
http://joel.reddit.com
http://dzone.com