I have prepared a list of working websites that allow you to check pageranks of multiple websites or webpages at once. These listed websites allows you to check pageranks of unlimited webpages at once.
CheckBulkPageRank.com is another great and free tool to check bulk pagerank. This tool responds a little slower however it works great. The best thing about this tool is, it gives you permanent link to your pagerank report so that you can check the updated pageranks later too or can send the URL to your client if you are working as a SEO company.
This is yet another a good tool to check pagerank of multiple pages or websites at once. This website allows you to check pageranks of 50 URLs maximum. There many other such sites that provide tools to check bulk pageranks however most of them do not work.
If you are one of those people who dont know what to do to increase your Pagerank, i will suggest you to simply build more backlinks and keep your internal hyper-linking system strong. Use nofollow tags for the sites with whom you dont want to share your pagerank juice. One important thing, avoid linking your blog with Bad neighborhood sites for any purpose.