You can also copy and paste the image URL directly from a photo on a commercial website like say, an RV vendor's site, into the image thingy here without having to have it on a photo hosting service.
Don't forget you can also control the size of the photo in a post. Nothing's worse than a series of full-size photos in a post that unnecessarily takes up nearly a full page... (and then some folks will quote the complete post and double post all the same photos again)
You can even copy and paste directly from someone's signature photo or photo in their message such as from the below post (without permission from forum member, hehe):
And you can make it tiny: