Google used to hate them – now it’s pretty good at dealing with them and doesn’t necessarily penalise them, although remember that Google isn’t the only search engine.

But there are still some issues with using parameters in websites. Mainly, they can result in there being multiple URLs for the same page. Google (and other search engines) may view this as duplicate content.

I think the advice to avoid parameters or keep them to a minimum is therefore still valid.

I agree with the rule about clean URL’s, let’s make life easier for Google and get every edge we can.