I use Photoshop Elements to do two things. First, reduce the size of the image to something more manageable. It will usually be quite large and I downsize it to a much smaller (you can specify either regular length dimensions or pixel dimensions). More importantly, after resizing there is a Save for Web option which greatly reduces the picture quality for web viewing. it wouldn't look good if you printed it but for viwing online it is totally adequate.

I think you can play with your scanner settings though adn reduce the DPI settings to reduce scanned image size. It's probably set pretty high but you don't need super high image quality for web posting.

lastly, your scanner probably came with a free graphics package that should allow you to reduce the image size and picture quality so look into that as well.

Michael