Linked from Ari's latest blog post is http://browser.garage.maemo.org/ which contains an install for a new Mozilla-based browser for the N800. It supports AJAX and plenty of other features, as you can see on the site.

This is a great step to replacing more and more of the closed source apps.

So... those of you that found sites that didn't work before, please give them a shot now and list them below.

Pownce now works perfectly fine... I can now post on it natively on the N800.