there are a few ways to do this and many scripts out there, a simple search on google reveals a few options. the one i use does a lot more than just check pagerank its an entire class for seo statistics. http://code.google.com/p/seostats/ check it out, it does google, yahoo, alexa, seomoz, etc, etc.
Gscripts.net is a fast growing directory of free php scripts such as php forums, php photo galleries, CMS , php e-commerce solutions and many other open source scripts. Each script has demo so you can test it before waste any time installing it, most of the php scripts offer direct download link. If you are planning to build a dynamic database driven site but you have little or no knowledge in PHP coding, Gscripts.net will help you find the php scripts that will save you extensive codding . We offer more than 48 content management systems that can be used as a base for your php / mysql site.
Hi nani, i am the author of SEOstats PHP class and just stumpled upon your post. There have been no reported issues with the Pagerank method and after testing again, i still can not find any bugs. But maybe you can let me know, what specificly not works for you, so i can have a look at it and (if needed) fix that issue. Thanks, stephan