Chicken legs. Vientiane, Laos. 1999.

I'd like to know if my scan is too dark for your monitor, or is mine

just too bright. I scanned this with an HP PSC 750 scanner at 200dpi

from a 4x5 print. The image was brighter in Photoshop 6.0 than here

at photo.net. I adjusted the curves and sharpened the image in

Photoshop. Any recommendations or is this OK?

Have you run through the Adobe Gamma monitor setup procedure? That will do a decent job on brightness, and it comes with photoshop. (The next step up from there is a colorimeter-based package like ColorVision's "Spyder" with PhotoCal or OptiCal software.)

Also, what color space did you work in? Sensible choices are things like Adobe RGB 1998, and Bruce RGB. Then, if you're saving the photo for web display, you really need to do a profile-to-profile conversion to sRGB (which is too small for serious photo use, but is a good approximation to an "average" monitor); this should give you the best chance you have to get decent viewing on the various uncalibrated monitors out there.

Finally, the photo looks a hair dark to me, but well within the range that's a matter of individual preference, not the sort where I'd say "it's too dark".