yournamehere

If you prefer looking at pictures, I see your point, although most full pictorials are over a hundred pics - which means browsing thru page after page (or lots of scrolling!). Saving them to your HD gives you the opportunity to view the set as a slide show. Before Windows had a feature for that, I downloaded Alchemy Mindworks' Graphic Workshop Professional.

If you prefer video, I find that most of the streaming online stuff is very low resolution - like 320 x 180 if you're lucky. Most of the vids I download are at least 640 x 480. I'm even starting to see 1280 x 720 scenes that are so hi-res they're over 600 MB for a 20-some minute scene. You won't find anything like that streaming online.

Besides - don't you have some favorites you'd like to keep around? There's no guarantee that anything online will be there tomorrow.

To answer the OP's question, though, I just archive them into password-protected *.rar files; then rename them to *.chk .

__________________
If you want to avoid 95% of internet spelling errors:
"If your ridiculous pants are too loose, you're definitely going to lose them. Tell your two loser friends over there that they're going to lose theirs, too."
It won't hurt your fashion sense, either.