Hi, I am planning a site that has a lot of large photos (using jcarosusel). I am concerned about the bandwidth usage and the hosting cost, are there standard ways of reducing the image size automatically? Thanks for any help with the question.
You can use a program like photoshop or picasa to resize the images to be web friendly.
I have a different situation, where I’m sort of hosting pther people’s photos, they upoad. So, is there anyway to automatically reduce the image size of photos people upload?
Well you could put a limit on the file size being uploaded, that would be one way of keeping a maximum on what’s being used. There are server-side scripts which can do that kind of thing. I would say for bandwidth considerations keeping images under 500KB (that allows for reasonable quality without insanely large loading times). 
As for automatic resizing scripts, there might be something out there, but I would worry about the lack of the user being able to pick how best to preserve the quality.