First time checking this out, seems to be a nice simple gallery. I did not see anything about watermarks, does V3.0 have options to include watermarks?
At the moment, it does not have it as a straight out-of-the-box option. We (or you) can add a ticket for this enhancement too. However, you can hack the script fairly easily (I think just by looking at the code) since the phpThumb (the library Plogger uses to created thumbnails and the mid-size images) includes a watermarking option. I can try to help you if you are interested.
I am interested but not for the site I am currently working on. My wife is a intermediate photographer and would like that option but it may be a while before I get that going. I will remember you though.