Hi,
You have to take in consideration Stumbleupon because this site have some good features as Stumbleupon toolbar as your boorkmarklet but 1000 times better you have to register with stumbleupon and download it to see how it is working:
StumbleUpon: Personalized Recommendations to Help You Discover the Best of the Web
Regards
P.S.: Sorry for my bad english I am french speaker