erm... go to the google search page, type in your keyword, and if you are on page one, your site is doing well. Then go to google analytics and check your visitrs and compare this to how many of those visitors signed up, or purchased from you. If its more than 10% you are doing well.
Then forget you ever saw the pointless little
PR bar and all the madness and obsession around it.
PR means nothing, it is just a way to reassure the dummies that they have not been forgotten.