sjinsjca
macrumors 68020
In case you missed his original post, he specifically mentioned the need to download PDF files posted from his teacher. Where you got video streaming out of that, I don't know.
OP said "PDA," and I didn't know quite what that was, but "PDF" certainly makes sense as an interpretation. My point is that there's a lot of content out there that can be downloaded from the internet using apps built for the purpose.
Ditto for web-based content, including .pdfs. I have an iPhone, not an iPad, but I can download .pdfs very easily. For example, I just used it to navigate to TraderJoes.com, clicked on Stores, clicked on Find A Store, and clicked on their Northern California link. Voila, a .pdf listing of the region's stores opened up in new window. Went back and clicked on their Southern California link. It opened a second .pdf in a different window. It also has no trouble opening .pdfs emailed to me.
I guess I'm still a little mystified what the OP wants to do.