Filtering is an essential Gmail power-user feature. With filters and labels, you can use Gmail to handle a ton of incoming mail. But managing filters itself is tiring job, but now more. Gmail Labs released a new feature dubbed Filter import/export that helps you work with filters in bulk, rather than just one at a time. The basic function is simple: turn it on from the Labs tab under Settings, and from the Settings > Filters page you can download a file containing some or all of your filters or upload a file to create a set of filters all in one go.
More info: Gmail Blog