The best way to find good pictures

When we did PS assignment and picture-relative works, we always face picture problem. Pictures are as important for our work as fresh raw materials for a delicious dish. I found PhotoXpress is a good picture database. There are a lot of high quality pictures (around 2000-3000 pixels), and most importantly, most of them are free. It included 22 categories, 352,798 pictures，and increased at the speed of 1000 pictures per day.
You can search the pictures you want through key-words or by categories.

And when you input the keywords, the result will be listed in two groups: one is free, and the other is premium. You can preview the big picture as your cursor around your objective picture.