I was motivated by this thread on the mailing list (and Gustavo's excellent Motion Tools) to work on a C++ ice node to provide a quick way of finding positions from an input texture uv array (the factory-installed UV to Location node doesn't work on polygonal geometry). The method doesn't require triangulated geometry.
Since we don't have access to pointlocators in the ICE SDK, the node doesn't actually get locations directly but it does generate a position on the polygonal surface from an input UV. The custom ice node is built into a compound that then takes the output positions and generates locations using Get Closest Location. You have the option of using the position directly or using the location port.
The addon is below for 2013 SP1 (64bit only) and contains C++ source code with comments on the barycentric and triangulation methods as well as notes on some of the problems/choices related to building a custom ice node. A sample scene is also included. If you find a circumstance where it doesn't work correctly I'd be very interested in the scene file.
Updated 28 June 2013:
Crash when no geometry under UV fixed.
Texture UV To Location v1.1
