Picasa Web Albums has finally improved the uploading feature. You can now select multiple images from a folder and upload all of them. After uploading images, you can add captions and delete the images you don't like. It's a long overdue improvement that's especially important if you don't use Picasa.
Another change is that you can now upload videos without installing Picasa.
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Picasa Web's new uploader uses HTML5 APIs, so it's not available in Internet Explorer, where you still have to install an ActiveX control.