I accidentally cleared the default bookmarks.

1. Is there any way to restore them?

2. Were any of them worth restoring?

3. When creating a bookmark and using the icon creator thingy, isn't there a site logo default of some kind? I recall glancing at the facebook logo (an "f") next to its bookmark before I cleared them all and I'd like to know how get it back. If done right, those logos are visually very helpful.