If you run a site that sells more than an handful of products leading you to have multiple category/result pages then you're best off also have a Product Index. The main reason is for SEO. You can set up a non dynamic URL to run this page which can then link to every individual product page on your web site. Search engine spiders can pick up this page and they'll follow every link through to index your products which of course could be great doorways to pull visitors in to your site.nnI've set this up on a few sites for clients and their index pages plus visitors went through the roof. This is the downside to using a dynamically run site as Google and most likely the other major spiders, won't index further than one dynamic URL. So if you have 'index.php' which links to 'category.php?cat=photos', these two pages should be looked at and in theory indexed, however the links from the category.php page won't be as the spiders are programmed to stop for fear of getting trapped in never ending loops. I have seen some deep linked pages get indexed before, but to be on the safe side a non dynamic URL for a sitemap should be in place. Of course you don't want to litter your sitemap with every product you sell, so this is why I started using Product Indexes.nnI first used one for SEO. I know, it's not really white hat but I then realised that it would be useful for visitors who just wanted to see everything in stock, like the index at the back of the Argos catalogue. I guess I don't always think the same way with online sites as I do with the way I do offline shopping. So now the index is available to visitors too. However a client said to me the other day, could I set it so that when the visitor hovered over a link they can see the product thumbnail. 'I've seen it on other sites' he said. Great, gotta love clients who say that, especially as the other site may have been using Flash or something that breaks all the accessibility rules (selling accessible work, it's often hard to explain to clients why other sites are in theory breaking the law).nnHowever, I left the idea in Dave's capable hands who dug up a few links for CSS only popups. Once I finally got the code in the right place (it's Saturday, what do you expect from me!) I got it working and I have to say, it's not bad! It's great for a dynamic product list, or results that don't display thumbnails.nnAnyhow, the code I used can be found at CSS Play.nnPS. Imagine if the Argos index used this!