Evernote is a fine tool to retain content for later retrieval.

I use http://www.evernote.com/about/download/web_clipper.php and later add additional comments where needed.

I also use a pocket size Moleskine to keep ideas/thoughts/daily-journals. Some of my coworkers/friends refer to it as my Dr Jones journal.

I use Evernote as well. I have one journal that is only devoted to my ideas and expanding on them. When I'm on the go, I sync on my phone using the Evernote iPhone app.

If you run linux, I recommend BasKet: http://basket.kde.org/

No concerns regarding privacy and trusting a 3rd party with your ideas?

Not at all. I'm not sure they are reading my notes and even if they did I'm not sure they are worth much without execution.