Salt,so sorry - this question didn't come up in my profile for some reason.
To use a Flickr photo without saving it on your computer:
Right-click on the photo and choose "copy image location".
Now go to the photo capsule in HubPages, select "URL" and paste.
Hit upload, add a caption if you like, and save.
Note you have to right click the photo to get the URL of the photo itself - it's not the same as the page the photo is on.
And for those reading this answer without knowing the background - you can use some photos from Flickr but not others. Use the Advanced Search, click "Creative Commons" and "for commercial use" and you'll get a list of photos you can legally use, provided you thank the author with a link in your Hub.