How to sync bookmarks between browsers on my Mac? Chrome included?

I use various web browsers

- Google Chrome
– Opera
– Firefox
– Flock
– Safari

And it would be much better if I could have the same bookmarks on all of them.

What would you suggest?

Apparently this one does it but it comes with a pricetag… http://cleanupyourmac.com/internetcleanup/index.html

Thanks!