you cant depend only on press release website to get you better pr and ranking. Though they do help alot but they dont stay for a very long time if you are targetting on mainstream keywords. You should try to focus on other factors also. (Just like you are doing with your signature link.)
The fastest way is to throw money at the site. I can have you in the top 10 for about 95% of keywords in 1-2 weeks, but it's expensive.
I agree with this.... This is actually effective in terms of Google ranking... Ive tried some of those techniques to some of my blogs and projects
You have to wait for three months from the starting the OffPage SEO. Re-check your content & continue the OffPage SEO processes as suggested by the other members.