Similarly to Ed, I take the pictures at high resolution, then I resize them using software. I read somewhere that it's better to do this than to take the pictures at a lower resolution. I don't need huge pictures but I prefer my eBay images to be square. First I resize them to 1280 x 960 (?), then I crop them with a 1:1 ratio. Since I'm working in Linux, I use Digikam up to this point. Next, I use Picasa to 'straighten' some of the pics. This allows you to make images look more level. I also rename the files in Picasa. Without renaming, I wouldn't be able to find the correct files for each listing. When I'm done, I resize again to 600 x 600. I sell records -- I take pictures of the labels with different settings (zoom, distance, light compensation, etc.) than the covers. It's the label photos that often require straightening. After all this work, which can take an entire day, I don't want to do a tedious upload. 35 MB just seems like such a small limit to impose.
Cheers,
Steve