What programs are you using and what steps are you going thru? At every time you
save (or copy) the file, can you find an option to choose the resolution or
size?

What software are you using to edit your pictures?

Gimp and others will allow you to resize, your images.

Or, you can do simple editing and resizing online. Photo Bucket
www.photobucket.com and Flickr www.flickr.com both allow resizing of images
as well as other editing.

If you are working from a dial-up location, likely you are better off
downloading free softwware like Gimp. If you have broadband, then doing it
online may be easist for you till you have time to select and learn a photo
editing program.

In Gimp, I use Image/Scale image. You can get pretty precise about the output
size.

I also use Gimp to adjust brightness and contrast, sometimes using the "auto"
functions, and to rotate pictures when required.

It's a nice program, well worth spending a bit of time to learn how to use it.

I also use Gimp heavily, but gThumb and Fspot - both of which come
with the basic installation - are fine for resizing images.

As far as command line goes 'convert' is worth installing. I've only
recently experimented with it. I'd use Gimp for re-touching and
modifying an image, but convert for quick resizing. I've spent hours
resizing manually on gThumb and had i known about convert i'd done the
job far quicker.

What about ImageMagick?

Command line tools there too.

Let me second Gimp is great. Especially for doing individual or
small numbers of photo's. But gThumb allows you to batch resize. This
is important when you have 600+ photo to resize. I copy them into
another directory and turn gThumb loose. When I get back, they are
ready to go.

You can use "The Gimp" for reducing the size and/or the resolution.
After a few trials you'll find the ratio that match with your needs
(what you loose will not be visible and the weight - in kilobytes -
widely reduced)

In the morning I came accross another possibility, in
Picasa. It solved the other problem, also, huge .odt files full of pictures. Now
I can make smaller files with a lot of images.