[Update: A friend from Microsoft says, "The UI switches to a more basic scheme if you're using a browser that's not recognised, for example the Firefox 3 and IE8 betas. What are you using - can this be the explanation?" Ah, indeed it is, no need to panic.]

[Update: Live seemed to have turned off all the cool features and are back to boring image search. What happened?]

Of the three main search engines (Google, Yahoo! and Live) Live search is streets ahead when it comes to image search. They also appear to be the only ones who are doing much innovation in this space.

So, why do I say such a thing? I'm not really talking about the quality of their results, because they're all about on a par. Live has a much better user experience. The first thing you notice is that they have done away with the concept of paged results. No more clicking 'Next', you just keep on scrolling down and more images appear. This makes a lot of sense for images for three reasons. First, image search isn't great, so users are much more likely to want to see a lot more results than a normal search for a web page. Lots of clicky clicky next just gets tedious.

Second, a thumbnail is a much better summary of the actual resource than the summaries currently generated by search engines. This means that users are effectively looking at the answer as they scroll through the results. They don't have to click on the result link and go off to evaluate a document and then come back, they can evaluate the image in situ, and therefore evaluate a much larger number of resources.

Third, it's more likely that users are not looking for an individual image, but for different images of the same thing. When they find an image they like, it's quite possible that isn't the end of their search. This brings me to another plus of Live; the scratchpad. When you find an image you like, Live allows you to put that image in a scratchpad by clicking on an image and selecting the appropriate link. Once the scratchpad is open, you can drag and drop to it as well. You can then save the images as collections.

Other interesting things to note include the resizable thumbnail slider and the image size filter (including wallpaper-sized images). Last, try filter:face and filter:portrait.