How do you design a web script macro that logs you in to a web site and...

...scrapes information? I am trying to design a web tool that logs in to a number of secure websites and negotiates through a few prompts to get different pieces of information that can be distilled into a static page. I know websites like Mvelopes does this with your bank accounts, loans, etc to provide an integrated financial picture. Much easier than you logging into 10 different sites and collating the information. I figured there must be some macros / PHP scripts etc for this already, as I am not that great of a programmer and would be challenged to write all this from scratch.