These exercises focus on JavaScript, Ajax and JS libraries. Some of the exercises should be done in advance. Once again, there's not much to do, so work on your project!
Note: There wasn't much about jQuery syntax on the lecture. (And this matters even less if you weren't on the lecture [because of language barrier].) That's because we won't introduce one library, just the idea of libraries. You can use any library you like!
On the lecture, Matti added jQuery and some effects to the image gallery. See without and with effects. If you need, you can save the XHTML, CSS and/or JavaScript for yourself. Don't worry about the Finnish, you don't need to understand it! But if you wish, compare it to the translated gallery from last week's exercises.
Check some accessibility perspective from lecture notes (in Finnish), from WCAG, or from (more popular and usability-oriented) Jakob Nielsen's top ten list.
On lecture, Matti did this cute JSON image randomizer (click the image placeholder). (Re)implement it with AJAX+JSON and the library of your choice. Note that AJAX doesn't quite work locally, so upload your stuff to fs/db.
Remember: it's not important what your topic is, what's important is that you do interesting and new things for yourself!