Tim,
If you can find Eustace St, the Irish Film Institute is there. Meeting House square and the Gallery of Photography is also found off Eustace St.
My favourite central restaurant, Eden, is in Meeting House Square:
http://www.edenrestaurant.ieOther restaurants I've been to in Dublin have been a disappointment, and actually, I got food poisoning about 5 times after moving here (after only once ever in my life)... Needless to say, you should watch what you eat anywhere.
Definitely check out Cafe en Seine on Dawson St, as the decor is really impressive (bar the ridiculous TV screens they use for watching sports). At night it becomes just another drunken watering hole, but it's great to sit and read the papers on a sunday afternoon. The service is crap and the food is average, but you'll be glad you've seen it, at least! Actually, their fixed-price lunch buffet was always good and they do a great french onion soup.
If you need camera supplies, see John Gunn's on Wexford St.
You should check out Powers Court which is a small shopping centre on South William St which often gets overlooked and has a nice atmosphere. Cafes, antiques, modern clothing stores, etc.
Mt Jerome cemetary is apparently pretty impressive (being very old and decrepit), and I've been meaning to visit it myself.
Actually.. if you want some directions, and would like to meet up, I'm in the city most days. Just a thought!
Seth