It's easy to install the bookmarklet. There are good instructions here. In brief, you either drag the big "Mashificator" button onto your Bookmarks toolbar (Firefox, Safari, Chrome; you may have to switch it on) or right click and select "Add to favourites" (Internet Explorer, save in the "Links" folder. Make sure your Links toolbar is showing, so that the bookmarklet is available all the time). You can also customise the bookmarklet with the form below. There are screenshots at the bottom of the page.
Here you can set whatever defaults you prefer for the bookmarklet. The standard one initially fills the carousel with Europeana content, having extracted categories and keywords from the webpage using Zemanta, but you might prefer other other defaults for either of these. You also get to say whether you want it to scroll sideways or vertically, how many pics will show at once, and whether it also shows the analysed text, keywords, and options menu (all pretty worthwhile I think, but you may disagree).
Here's what it might look like if the bookmarklet is working right:
For this, I went here, selected the first paragraph and hit the bookmarklet (before I added all the APIs currently in there).
Kittens are good too:
Got problems? Got huge admiration? Contact me (@jottevanger on Twitter).