Modern browsers are, generally speaking, so much better about stability than they used to be. Still, who hasn't had a browser crash in the middle of filling out a form at some point? Maybe the odds are 1 in 100, maybe they're 1 in 1,000, but it will happen. Now, consider the odds for all the people visiting your sites. If your site has forms of any kind, you should consider using Sisyphus to add Gmail-like saving to your site.

Sisyphus is a jQuery plugin that adds form protection to your site. It's easy to add protection with Sisyphus to your site, it requires just a few lines of code and then Sisyphus does all the work.

It uses local storage to save users' work, and the storage is freed up as soon as they reset or submit the form. It works with text areas, dropdowns, checkboxes, radio buttons and selections. Alexander Kaupanin, the author of Sisyphus has adding fields to exclude from observation on the todo list. That means that, eventually, you'll be able to specify individual fields that won't be stored.

According to the Sisyphus homepage, it's been tested with all recent releases of major browsers (IE, Chrome, Firefox, Safari and Opera). Sorry, Lynx users are still out in the cold. Sisyphus is available under the MIT license, so it should be suitable for pretty much any site. If you're looking to test it out, try the main page with sample form, and then grab the code on GitHub.