Graphical alert on a change to web page

[Mr.Noobsworth]

I'm super new to this, but I was wondering if anyone could point me in the right direction to accomplish this or if anyone could offer advice? Basically I want to make a module that scrapes a web page and if there is a certain change to it I want a certain graphic to display on the portal. The module itself would have like five or so graphics that would change from green to red depending on the web page status. If at all possible I'd like to have the forum user be able to set up a certain amount of their own urls to check via a profile setting too, but if that is too hard I suppose a static list of urls would suffice.

Thanks for any advice/help