http://www.gimp.org/

http://www.blender.org/features-gallery/

There is no equivalent. Photoshop cost big money and nothing in Linux does.
:)

The GIMP has many Photoshop features, but is not equivalent. It is good
enough for the average user, but pros will find it lacking. The interface
puts some people off, but you can get a PPA for the latest beta that
provides a single window mode. Krita is good and so is Digikam. They are
more equivalent to Elements than Photoshop itself. It all depends on what
you are looking for and your level of expertise. Many who use Photoshop do
not pay for it and do not use its powerful features.

There are even more powerful applications used by studios and high end
graphics pros, such as Blender and Cinepaint. There are many specialty
applications such as Povray for Raytracing, Luminance HDR and RADIANCE
Lighting Simulation and Rendering System. There is no shortage of tools,
just not one killer app for all things.

I suppose asking for an equivalent is overkill. I don't need the power that
studios have. I just need some features that are commonly referred to as
photoshopping.

Depends to what sort of level you want to go to. For simple
adjustments to brightness / contrast / straightening / red eye removal
etc then Picasa is as good as anything. For more advanced work then
Gimp is good but there's a learning curve to it ( same as any other
advanced program !! ) but once learned it's pretty powerful.

Two things to remember:

1) Quality of image cannot be improved - a low res snapshot will
always be a low res snapshot.

2) Work on a backup copy, not the original image

I'm working on an image of Sharona--the REAL Sharona who inspired the song by
The Knack. I had the album but don't remember the picture of her inside...

Anyway, I want to send the image to friends and ask them if they know who it is,
but I need to edit the Knack album out of the picture because that would kind of
give it away. I'd like to use the colordropper to use the color of her shirt
and pants to eliminate it and make it look like she wasn't holding anything.

Will some of the mentioned programs do that?

You can do that or you can just cut and past the part you want into a
new image and remove colors or use the eraser to erase parts of the image.

The clone tool in the GIMP should take care of that nicely. You press Ctrl
and left click to copy what is under the adjustable clone cursor and then
just left click to paste the cloned part over what you want. It produces a
better result than the eyedropper because it allows gradations and textures.

If it's the picture I've found when searching for Sharona Alperin then
the album you can just black out and it won't be obvious that's what
it is she's carrying :-) There are also other images of her that you
can possibly use to confuse your friends even more

The photo I'm using is hawt. Easy to see why she inspired him so.