PDF Printer is a Cydia Tweak that let you allow to save web pages as PDFs and adds Print as PDF functionality to Safari web browser on iOS. This tweak is available free for download via BigBoss repository.
After installing PDF Printer just open a web page in Safari, then you will observe that under the “Print” option from the menu, you can select “PDF” button to convert webpage into a PDF, which you could save and open in supported applications.
Now, just give a try to PDF Printer on your jailbroken iDevice and write your experiences in comments.