Susie, just note that what you are esentially looking for is freewebspace with a service that you can steal bandwidth only. Not sure if you understand/realize/intend this, but this is what you are doing regardless.
I'm not sure, but some of the big boys have recently been preventing hot-linking (linking to directly to files from another server), and geocities might be one of those. Your viewers will see a broken image if the provider you pick does this, even if you linked it 'correctly'. Just something to be aware of, so that it doesn't drive you crazy.
A internet hard drive type provider might work better, but there are different ones and I'm not familiar with how they all work exactly so I can't recommend anything in that area.
Either way, test it with one picture.