"Yahoo is making a major push into search personalization and recommendations - the overall project is called "Shoposphere" and the major feature being released is called "Pick Lists". Their goal is to move ecommerce towards what they call "me commerce". Any registered Yahoo user can create a Pick List."
The Yahoo Shoposphere site has more details on Pick Lists:
"Pick Lists let you share the stuff you love and the stuff that matters to you with everyone or your friends... on the Shoposphere, throughout Yahoo! Shopping, by email, and even through RSS feeds.
Make a good one and it could even show up as one of the highest rated Pick Lists on the Shoposphere."
More analysis from me as I look further into it... I do like the "me commerce" bit :-).