This may be old news to some but it's something I've only just discovered.
I've been happy with the Postimage.org image hosting site as a reasonably easy way to add images to TNF posts and also to create themed galleries, which you can invite others to browse and even download from (though always best to keep images small and clearly watermarked, of course). And all for free, though here comes the 'Yes, but ...'
I'm not sure if it's a recent development, as I don't offer the browse gallery/download option that often, but someone I recently invited to view a set of my pics there mentioned that their visit included a sidebar of 'interesting' ads, featuring buxom females offering various athletic services. I couldn't see them myself - no sniggering please about the effects of certain habits on eyesight - but a friend I invited to confirm this development was offered various weight-loss programmes - so the ads presented clearly depend on the sort of cookies you have lurking on your system.
The aim of the Postimage people is not surprisingly to persuade you to subscribe to their new (?) Premium service, which in exchange for me paying about £70 a year offers my visitors ad-free browsing of my images. I've yet to confirm this works in practice but, whatever you may mutter about a fool and his money, I've opted into their Premium service, as being the hassle-free way to keep my images on there, rather than relocate them somewhere else that's free (at least for the moment). No doubt this post will prompt a deluge of such suggestions.
Of course, it does mean some loss of entertainment opportunities linked to any received complaints,given the tailoring of the presented ads to the browser's proclivities - but despite that, I think it's worth knowing about.