I've just written a review of Elizabeth Kostova's novel The Swan Thieves (a fine novel) on Wikio Experts, a writing site I joined recently.
The site works on similar principles to Demand Studios, in that, once approved, writers choose from a selection of titles to write and submit within a few days. Wikio Experts is a little different in that payment is a mix of revenue and outright payment, so that for some articles you will definitely get a set amount, say 5 Euros (the site pays in Euros), while for others, you can earn "up to" 15 Euros. It is early days so we'll see how it works out, but another site offering outright payment to non-US writers is very welcome.
Joining Wikio Experts happens in two stages; you initially fill out a brief application form, then, if approved, you submit trial articles on the topic areas you want to write in and if the articles are accepted, you can then select articles to write. At a maximum of 400 words, the articles are not too onerous to write.
The selection of topics at Wikio is as random as at Demand Studios, but, at the moment, there seem to be much fewer titles available. With Demand, it is usually possible to find something doable, once you've scrolled through the weirdness and the impossibly (for me) technically specific, but, with Wikio, I wonder whether supply will meet demand. It seems like a good thing, on the whole.