The above link is an old electric meter box that I found in downtown Boonville, Missouri. The aged and weathered look of the paint on it caught my eye as did the contrast of the color of it vs the color of the nearby gutter shown in the image.
The above link is to a photo of an old side panel on a dumpster that I shot a year or two ago. The rust patterns are interesting and might work nicely as a texture map or bump map in a 3d modelling software if cropped to meet your need. Alpha may need to be adjusted so that its not so dark though.
This is an old stop sign that I found in downtown Boonville, Missouri. This old bent sign sitting at this location seems to tell a story. I like the composition here and the contrast between the bricks, the sky, and the red of the sign vs the pole texture. There is a lot going on texture wise.
This is the backside of a dumpster that has been worn down over time. It looks like the patterns on where the paint has been removed has happened due to rubbing against the collection truck as it is emptied. I find the swirly patterns to be rather interesting.