Buster Answers allows you to 'star' things that you think are useful, so you can easily get to them later on.

For example, say someone posts some great advice about how to do a chemistry calculation. You know you'll want to come back to it later, or you think it looks really useful, so you click on the star next to it. It will appear on this page when you're logged in, and you'll be able to access it quickly forever.

Just log in to be able to do this. It's free!