I do the vast majority of my tweaking/edits in Picasa. It covers 90% of my needs, including adjusting color tone to a limited extent.

Without trying too hard I came up with this using your original photo in Picasa:

Not too shabby and pretty close to your "fixed" image, I think.

It will even do a bit of tweaking on RAW images, though not nearly as much as a true RAW processing tool.

Photoshop is a great product, but it is very expensive unless you actually need the features it offers.