Search for a 'fast free directory submission software' or similar and you'll find something you can download and submit to a large list of directories including high and low PR. Spend some time doing it when your waiting on a download or have nothing to do.
Rubbish idea.
It will blacklist you in most desirable directories because getting listed for free requires your visit to directory submission form and by following submission guidelines that script can’t do.
Of course it still helps you gain backlinks. Just make sure you get the right category for your site... And I agree with some of the replies here that you don't need to pay someone just to submit your site to directories. You can do it by yourself..
I was thinking about hiring a company to submit my website to some high PR directories. Will this bring up my PR or is it a waste of money?
Yes buddy if you are thinking of PAGE RANK alone, then certainly yes it will help you to increase your PAGE RANK. On the other hand PAGE RANK has no connectivity with your actual rankings. So you got to select whether you want to see an increase in PR alone, or increase in page rank. If those directories ( irrespective of their PR) are ranking high for your targeted keywords, then it will help you score higher rankings on search engines for those specific keywords. If your directories are not ranking anywhere , but having a PR 7, then it wont help you in search engine rankings, but your GREEN BAR will increase. You got to select whether you want to spend money on GREEN BAR or HIGH SEO RANKINGS