Windows only: Splashtop, an instant-on, web-focused OS with Chromium, formerly pre-installed on laptops alongside Windows, has gone and made itself a free download. The catch? It's mostly HP Mini and Pavilion laptops, and one Compaq, that can run it, for now.
Which HP/Compaq laptops? Here's the compatibility list. For those who happened to pick up the right kind of PC, though, Splashtop does look pretty handy. It books quickly to a minimalist OS that features Chromium, the open-source version of Chrome with Flash pre-installed. There's a search bar powered by Bing. Two big buttons make it easy to get back to Windows or power off/sleep the system, and your Chrome start tab panels make up your desktop.
If you're able to give Splashtop a go in its new download form, tell us how you like it in the comments. It's a free download, and installs through Windows.