I got a few backlinks (500) from (3-5)PR sites, do youn reckon I need to use a link pinging/crawling tool?
I can't see any of these links on google webmaster tools, it's been a week since I purchased those backlinks.
You really can't go by webmaster tools completely because it doesn't reveal all of its information to you. Its just like anything out there, you gotta take it for what it is. I would also say that pinging wouldn't hurt the sites.