If I find something interesting enough that I think I would want to reference it later, I have taken to printing it to a PDF file, and saving that file. If you don't have a local copy, you never know how long it will last.
I've begun archiving thing like that with Evernote. It helps me tag things, and provides a searchable archive accessible from all of my devices.
I keep on meaning to try out evernote. It seems like it would work well for me from what I have read about it.