Too often do I see this. Ever been to a site where you're looking for something in the navigation and just cannot find it only to find out that there's some monstorous button that you can't believe you missed that has exactly what you want?

Two examples

Uh oh. It's a shot of the jEdit homepage.. the site of my second lover. How dare I criticize.
This is only a somewhat-example because jEdit's doing the right thing actually. I'm sure now that I've mentioned it you already spotted the big download button at the top right.
But what if you didn't? When you look at the site you may expect to be able to download jEdit by using the menu on the right. You would promptly move down the list to find it on there and click on the link. If that link were not there you could be lost for a little while. jEdit's site displays a very good way of using redundant navigation. An example of what *not* to do would be to remove the link from the list and only leave the big button at the top.

It's not only seen in standard site navigation though. Imagine a site where people can't buy your product even though the button is right there. Seybert's "Add to Cart" button is actually more hidden than it is visible. The average user may pass right over this button because it is so out of place. The vibrant colors and logo-esque design make it look like more of a promotion than an actual button. Because of the placement right next to the plain looking checkout button many users may be tempted to hit the checkout button instead because it looks more normal and form-esque; something the user expects.

How to remedy

Don't use buttons that stand out too much and/or are out of place. People expect to find things in certain places. If you're going to have side navigation, put everything your user will want to find in it. If you want to make it stand out probably the most you should do is make the text on your link bold. Don't move the link somewhere else; Even putting it at the top or the bottom of your list of links could cause confusion because some might pass over it thinking it's a header or a footer element of your navigation.