Good gifts for photographers?

Hey photographers!

What are some must have photography items? What are your favourite items?

I'm looking for some good gift ideas for my sister and her partner. I would describe them as "semi-pro".

Thanks!

What gear do they have and what's your budget?

It could be as simple as a circular polarizing filter or as deluxe as a new lens, but it all depends on what they currently have.

Some idea's off the top of my head (aside from a circular polarizer) are:
-Graduated Neutral Density filter (2 or 3 stops is most useful)
-A flash
-A camera store gift certificate

Cheers.

There are some really cute "Im a photographer tshirts"
I got my friend this one..


there are a bunch all over the internet.. funny ones to artsy shirts.

Also camera bags tend to be these ugly black..things.
but now they are starting to make pretty ones lovely gifts

My favorite items is my camera bag..

I got mine from here. they are really pretty and just amazing camera bags!
shootsacs are very popular with prof. camera peeps (guys and gals)
The Shootsac Lens Bag | Changing the way you shoot!

gift cards and stuff from here and probably pretty useful. Every photo major I know worships this store lol
B&H Photo Video Digital Cameras, Photography, Camcorders

What about a nice Domke bag?

One of my favorite online stores for unique stuff: Four Corner Store : Your store for all things Toy Camera — Welcome

a giftcard to have photos developed into prints, canvas, albums, and throw blankets is always welcome.