everytime i put in -moz-border-radius or -webkit-border-radius css attribute it spits out an error saying it doesnt exist, making my css3 page invalid, even though ive been told they are css3 attributes.

so my question is should we be coding for css3 just yet?

the CSS3 property will be border-radius, what you have used are browser specific properties which of course, are NOT valid CSS3 property names.

Yes it is far too soon to be using CSS3 on mainstream websites. if you are making a cutting edge showcase for CSS3 then fine, but generally you are just creating extra work for when CSS3 support becomes more than purely random.

I've used -moz-border-radius once recently, and then complemented it with -webkit-border-radius, (Safari and Chrome), but I had to use background images for IE since it doesn't support anything similar. I did it this way because I was having a hard time getting the <select> boxes to take on a background-image correctly in Chrome, and wanted it to be consistent with FF. In IE, the images were working fine and I left it as it was originally designed, because what else was I going to do?

As far as those properties not validating, who in their right mind cares about CSS not validating?? One of the laws of CSS is that if the browser sees something it doesn't recognize, it will simply ignore it, so invalid code like this will never, ever break anything in the future.

Especially when you start to work with cutting edge languages like CSS3, I find you'll drive yourself crazy trying to learn it while being completely valid. As wayfarer says, who cares? It's a nice thing to have, certainly. But if it's keeping you from launching a new design, forget it.

Basically what you're looking at here is progressive enhancement. Your aim should be to provide the nicest experience possible for users with the latest browsers while still maintaining enough backward compatibility so that users with older browsers (cough, IE 5) can still use your site easily.

I don't know about IE5, as the sites I build aren't likely to be browsed by bushman tribes in the jungles of South-America, but (*cough IE 6*)