Easy Rounded Corners: jQuery Corners
jQuery Corners is a jQuery plugin for creating nice-looking, anti-aliased rounded corners without using any images.
The plugin is unobtrusive & works well with all major browsers including iPhone.
The corners to be rounded & the radius of the corners can be easily set.
And, a great feature is the ability to round form buttons.
Update 26.01.2011: The URL of the resource is updated as the developer's website is no longer available.