That's a rather high end SLR camera - nice gift.
I'd go eBay for a lens and maybe look for a grouping of
lenses and filters...
Other good gifts for a camera buff are tripods, camera bags, neck strap, instruction books.... all easy to buy and you don't have be an expert on the camera to know you're getting something that "fits".
Here's the coolest tripod ever -
It called a Gorillapod - very cool.
By the way - earlier this week I shopped
Ritz Camera and they're having a great sale... I ordered on Sunday and my order shipped on Monday!