From about : It's a Delicious clone. Yahoo! announced that they were killing Delicious and I said "well, shoot", because I like Delicious and I've been using it approximately forever. Then I said "Well, I can write my own". So I did.
How long did this take? About 10 hours.
Link : http://1r7.net/
Update : seems that the Dutch company Symbaloo has interest to take over Delicious.