It checks the PageRank of a given url in 32 data centers.
It`s easy to install, just copy all the files to your server.
To remove or add data centers you simply have to edit a text file.
I used http streaming, but since it does not work with Ajax, Firefox 3 and other browsers will return the results in a different style (one at a time for Firefox and all at once after all the results are loaded for other browsers).
Requirements: php5 and cUrl
Price: $10 Buy