Photography enthusiast site 500px has a new tool that lets you search for photos by sketching them. Have a vague idea of what you want to see or a memorable picture that you haven't been able to find? Just channel your inner Van Gogh. Of course, drawing an image with your mouse on the virtual canvas won't allow for much accuracy, but you can utilise a colour palette you like to search for a scenic scene. The photos are primarily landscape photography and you can then buy them for your own use or even order prints. Colour is really key here -- you can try to meticulously draw a lighthouse, for example, but the tool extrapolates your broad strokes and colour choices more than your intricate intentions. You also search for animals, portraits, travel and city photos that match up with your palette, and the search results update with every stroke you add to your drawing.