mike, picasa 2 is a free program available from google @:
http://picasa.google.com/download/ that i use quite a bit.
it is a pretty cool "file management" program and has some pretty nice and easy manipulation features also, including some of those you mentioned. and, the price is right.

obviously photoshop is pretty much the state of the art, if you have a spare grand or so lying around,

but in my efforts to use it, i found it to be a very difficult program to master. but man, if you master it, you can do some amazing stuff.
i did some very minor manipulations on the mannequin pics, like color saturation, cropping, etc with picasa. thanks for the comments.