Point & Shoot or DSLR?

It would be a Sony Cybershot Tx9 vs a Nikon D3000
I want professional looking pictures but also easy to use (for my dad will be taking most of the pictures) for a trip to California.
What's your oppinion?

Producing "professional" looking photographs has much more to do with your skills, NOT the camera you use
However, the Nikon D3000 has a sensor that is over 15 times larger than a P&S camera like the Tx9 and it also uses interchangeable lenses from fisheye to super telephoto lenses
The Tx9 has a very limiting 4x optical zoom on top of everything else

I wouldn't suggest getting a DSLR if you aren't serious about photography because they can get really pricey. Point and shoots can produce some really nice photos too. Maybe try getting one of the hybrids they have out right now. Nikon has some point and shoots that are kind of like DSLRs. Look into one of those as a possibility. I'd go with a point and shoot though in your situation.

Nikon D3000. Great quality and very easy to use/figure out.

Interested in learning manual controls == Nikon D3000
Not interested == Sony Cybershot.
Since you will be on vacation and do not have much incliantiation for serious photography, my suggestion is to stick to the simple point and shoot. It will be a lot less hassel to figure out. In addition, using a Nikon the same way you will use a Sony Cybershot, will produce similar results. It will not make any professional looking pictures.
Go get teh Cybershot.

If you put your Nikon D3000 on "automatic" mode, it will function like a point and shoot camera.
So the answer is obvious. Get the DSLR.