Geez...I must be loosing my mind...sorry about that!
Anyway, Chuck, Adobe will let you resize both the physical and resolution dimensions in 1 step...in 5.0, go to Image/Image size...set it to 600 width (make sure to constrain proportions or it will screw up the height of the picture) and set your resolution to 72. The 600 width means it can be displayed on *all* monitors and all monitor settings without forcing a scroll bar...most of your Win2000 and older platforms will be on 640x480 and an image wider than 600pixels will be HUGE on their screen...and 72 resolution is PLENTY for anything on a monitor. And to crank down the file size even more, do a "save as", select .jpg/.jpeg, and set it to about "medium" (3)...and you should be golden.
I know Photobucket and some other photo hosting sites resize them for you, but I don't think there's gonna be any easy, 1 step way to convert them...