Think that anchors within a page as you are suggesting use a # and not a ? but the idea is there. This system is often use on FAQ pages where you have the FAQ at the top and then it links to the answer lower down the page.
Once you run to several pages of text may want to split it so you don't have to wait for that very long page to load!
I would advise against using a pop-up window since lots of people do your popup blockers, and I think even the next release of IE(SP2 for XP) will block popups without a third party plugin.