Note: Keep in mind that only when rotating JPG photos does this question of degrading or damaging the images arise. Other formats such as tif, psd, etc., do not have this issue. There are several batch methods in different versions of Photoshop and Bridge that will let you rotate images, but when dealing with JPGs there may be an issue of the degrading process.
Technical Note: The reason that rotating a JPG degrades an image is because when you save the image, it is recompressed and since JPG is a lossy format more information is thrown away each time you save as JPG. The usual way to work with images that start as a JPG (such as from a camera) is to save out a working copy in PSD or TIf and then you can do whatever you want and never lose any further data. When you then convert it back to JPG for posting to the web, you'll have the maximum info available.
Further Note: If you do lots of Photoshop work and you find that your photos normally need Photoshop work to make them their best, then you should consider shooting RAW where you will have the maximum data. You then do your rotate in the RAW converter (and this can be batched) and their is never any question of data loss.
"The map is not the Territory"