How to learn PR without toolbar

as i software developer, i am in the feasibility study for a program:

specifications:
you will give the program a domain name.

-it will get backwards links of the domainname.
-then it (the program) will visit each page showed
-find the PR
-get (parse) how many internal and external links are on that page

then i would probably make some analysis and research to make some assumptions:
eg. if the external link count / internal link count is larger than 10, then this page is a reciprocal link exchange page or a farm.

these data can be used to find the best pages to contact for link request.
eg. the ranking may be based on PR / total number of links.

i will definitely setup a rule that enables the user to change the number of seconds between queries to web pages. so that i dont get myself banned or will have any load on any servers.

I dont think there will be any problem with this program in terms of guidelines of google. it will only query the first 5 pages [user defined] of the backwards links and relevant pages that show up.

so, theoritically, google will receive 5 queries and all other web pages will receive 1 http request.

THE PROBLEM
=========
I am only stuck at getting the PR of a site

Does any of you know how to get a PR of a site?
Any API may be?

I remember a discussion going on. Some ppl could not learn their PR using a Mac, so they called a specific url, with their domain name as a parameter.

Any suggestions or comments. thanx

darrin, u once mentioned that the real PR is multiple of 4 as you increase pr.

such that:
if PR 4 is 100 as a value, then PR 5 is 400.

this also suggests that you have to work 4 times more inorder to increment your PR.

i know there is not a proven fact and this is your belief.
can u comment on my idea below:
technically,
a link from a PR 5 page with 25 links would do the same good as a link from a PR 6 page with 100 links do.

do you agree?

i am considering conversion from PR to real PR, so the function of the program will be more logical.

kind of weird to reply to my own post second time and being the only one

this page suggests that the real PR is power of 6.

http://www.miswebdesign.com/resources/articles/pagerank-3.html

also, information about how to get PR using browser. it says that google toolbar generates a checksum which sends it as a parameter. so there is no way to call a url to get the pr of a site, coz we cant guess or calculate the checksum ourselves.

but, there is always a way to do stuff. i am thinking of open IE with google toolbar installed. i noticed that the PR of each site stored in some random way in temporarily files dir.