PODing to the majority here. I think it's unethical to photoshop.
To add to the discussion, my problem with it is that attraction is a subjective reaction. If I got together ten of my friends and rounded up a few brave men, I'm sure we would all have a different idea of who was hot (or not) and why. The men's appearance is objective. They look the way they look. Wavy salt and pepper hair isn't attractive or unattractive until someone reacts to it. It simply is what it is.
By photoshopping away essential features from your friend's image, you are taking away potential mates' ability to see her objectively, which means that they have no chance to decide if they are interested subjectively. If these changes are making enough of a difference that they seem to be "worth it," then they are probably making enough of a difference that your friend isn't really portraying herself as honestly as she could be. As with others, I don't object to Photoshopping out things like red-eye or a piece of spinach stuck in your teeth, as they aren't there all the time. However, I'd draw the line at whitening teeth or photoshopping out freckles.
Anyway, the problem with misrepresenting herself is twofold for your friend: one, she could be meeting guys who find out upon meeting her that they aren't interested (either because she isn't as attractive to them as they expected based on the pictures or because they think she's dishonest for posting altered photos); two, men that would be interested in her normally might pass her over because her "improved" photos make her less intriguing to them. Neither situation is ideal.
I agree with the PPs who suggest that the best option is to have a mix of photos. She should have some of herself dressed up for a date or outing, some of herself in a more casual situation (no, she doesn't need to be in paint-splattered sweats), and a few of her doing something she loves. Best to be real.
