It was said I think - it depends on your product, and your preferance - but also your method. I mean depending on the overall image you are striving to produce, pictures can go a long way to help reinforce that image - depending on WHAT you post & HOW you post them.

is a great example of using personal photos to reinforce their desired image.

wishes to appear very professional, extremely personable, easily accessable, and decidely approachable. This is reinforced in a number of ways - including the fact that everybody has their personal picture displayed on the web site.
(See them HERE)When you talk to that individual on the phone - you get the feeling that you are truely 'connected' to the heart and soul of the business. (I mean seriously - has anyone ever talked to the CEO of another 'real' hosting company..?)
To me there is nothing as frustrating as getting the run around from some 'faceless voice' that doesn't give a rip about whether or not your issue is resolved. In this way the psychological advantage of face to face relationship building is revived on the otherwise service dead internet.
If you have a service oriented site, then NOT having pictures would be a huge disservice to your efforts.
If you have a product oriented site, then it really depends on your product, and the market you wish to reach.
If you sell high end home decorating items, then you could be doing yourself a favor to have a professionally photographed image of a room decorated with your items, and you gracing the center of the layout(think Martha Stewart pre-incarceration), but you would probably want to refrain from posting a dimly lit picture of you in sweats and a dirty t-shirt, hair pulled into a make-shift bun(complete with pencil to hold it in place) holding various trinkets available on your site.
(sited from an actual site I once saw - ruined the image completely- talk about "Pay no attention to the man behind the curtain" sheesh)
Anyways, thats my 3.5 cents.