I'm currently using it for adjusting color levels and curves. I hardly use the advanced PS techniques for my pics.
It's an open source software, so it's free for anyone to download and use.
It works well generally, however there are a few number of tools that are available in PS is not available in GIMP. You can think of it as a slimmed down version of PS that looks ugly:bsmilie:..other than that it's free.