I was searching for some information about my camera, when I came across to http://www.testfreaks.co.uk/. It is similar to ProductWiki that Raj reviewed below, but where people are also rating items that they own or just they have tested. You can find ratings for almost every electronic item you want to buy, from cameras to microwaves. They include numerous categories and each category has its own specifications for rating. All items have a global “Freak Score” which is the overall score of the item out of 10. You can also find some other useful information about the items, as were to buy it and its price.
We can include a similar but more simple feature to Shopster. Users will be able to rate items they own. The user would be able to write his experiences with the item and put a mark to some categories. These categories could be some global ones as value for money, build quality, performance or something similar, ease of use and an overall score. We can then add a product search to the application and the results will show shops with the selected items and of course its overall score.