In my demos, I'd like to avoid using traditional DBs and store all the data on the client side, e.g. information submitted via a form.
What alternatives do I have for that. I've heard about Gears but I don't have any practical experience.
Can I also store binary information besides strings, e.g. an image?
You may have a look on YUI's StorageUtility. It can use HTML 5, Google Gears or SWF on a fallback basis.