I have a tab with about 8 reports on it that I reuse by basing their queries on a URL Parameter. And pass a different URL parameter when calling the page from different links. I'd like to put a  le on the top of the page somewhere that corresponds with the URL parameter. Can anyone suggest how I can grab the URL parameter and display it in an HTML module? Thanks!

This is a relatively common task, and you can do this with javascript or jQuery.  You'll find one approach outlined here.

As for doing it in a text html module, you can use an html module to place a div in the appropriate place, and use the javascript/jquery to place the value of the querystring variable in the div.

Since you mentioned the word "reports" I'll just mention that the DotNetNuke Reports Module is able to use querystring parameters in creating reports.  There are other modules that also make use of querystring parameters.