ECN- sorry I couldn't negate that rebuttle. My Mac source went legit (wtf, right?).
Anywho, don't go for the HP. Their build quality is very poor. Their keyboards are very cheap and have lots of issues that HP is not willing to fix. Dell, believe it or not, has great customer service. The only catch is you have to call through Dell Business. I can't really speak for Sonys. They used to price themselves too high for mainstream, but anymore, they're all the same. I will recommend looking at Asus and Sager. They along with Clevo produce most of the world's laptops. Asus has some really nice looking stuff (and powerful, too). Since you're into graphic apps, I would definitely look at getting a higher res screen. I consider WSXGA to be a good fit for a 15".