Just about every photo editing software I've seen allows you to see the EXIF data (EXIF data is the aperture, shutter, ISO, and other data.) Photoshop has it, Paintshop Pro, I imagine Gimp. Also, the lesser programs also allow you to see it. ACDSee as Spankmeyer mentioned, ThumbsPlus and IrfanView both show it. Usually you can go under Properties in the File menu to see the EXIF data, or sometimes it is just labeled as "Camera Info" or something similar.
Opanda is a free download to allow you to view EXIF. It also allows you to right click images on the web and display EXIF unless the data is stripped. I can't see EXIF on DWB's photos, but the first photo of Taavi(EST)'s last posting was taken with a Pentax K-m in Aperture Priority at 1/100 second, f/11 aperture, ISO 100, -1/3 exposure compensation, 55 mm focal length with no flash and auto white balance. He also has his camera set up to process the JPEGs with hard contrast, low saturation, and normal sharpness.