Koinup Places directory, where you can find Second Life places discovered/shared by Koinup members. If you're looking for new places to visit (and use them as set for photoshootings) you can browse the most recent places section, while if you're looking for highly popular places you can visit the "most coolest section".
Some of the most authoritative bloggers are adopting the Koinup Places as guide to discover amazing places to talk about. Here you can read an interesting story by Strawberry Singh based in Atrum, an amazing Second Life sim, discovered via Koinup Places
(above a lovely picture by Strawberry Singh)