Ok, this one is really a tip for any website. Do not duplicate browser functions.
Have you seen sites that have a link, and maybe even an icon of a little printer, with a ‘Print this page’ function? I have… I’m also pretty sure that almost every single browser I’ve used in the past 11 years has had a print function, just like 99% of the applications I use everyday. So why? Now, if your print function actually does something besides just bring up the print dialog, perhaps there is a case for it (though with CSS and print style sheets this is less relevant nowadays.)
It’s like a newspaper printing dotted lines around every article, just in case you wanted to clip it out and save it. Really. It is. one more time folks, Do not duplicate browser functions!