Have you seen the Blooming Advantage Plant Finder? Blooming is an exceptional grower of unusual plants, and Northwest gardeners see their purplish pots in almost every nursery. They are best known for their perennials, but they grow a little bit of everything (well, not trees, I 'spose...).
With the Plant Finder, you can search by name to learn about the habit and cultural requirements of a plant or you can input your requirements, such as sun exposure, flower color and height, and the Finder will generate a list of plants that meet those requirements. Most of the plant descriptions include photos, too. Cool, hunh?