My friend Vincent has started up a social shopping service called Nuji. Nuji allows you to save your favourite clothes, music, books and other products both from online stores (with the bookmarklet) and in the real world (with the iPhone app). Because people can follow others with similar taste, it's a really nice way to discover products through other people.
Essentially if you're online and shopping, you click a bookmarklet and it adds it to your Nuji scrapbook. Then you and your friends can check out the things you're shopping for.
If you have an iPhone you can tag stuff in real life using an app and barcodes.
So far I've discovered new places to shop for things for our house, and might develop the ability to feel shoe envy late in life. Check out my Nuji stream.
Here's the problem. I am getting all my shopping advice from friends of friends. Where are you? If more of us sign up, we can all get more interesting advice and ideas for shopping both online and in the real world.
So check it out. At very least you'll see some of the odd things I shop for (e.g., this Japanese cold coffee brewer: http://bit.ly/id0dPl ).