Boston area people: also see the Boston-specific page for meetups, etc.
This page is my own take on worthwhile 3D print related resources. Mostly it's a collection of links, to the left. These are my personal opinions; I'm open to suggestions, email me. Quick link to this page is bit.ly/info3dp.
For modelers, I don't include SketchUp, a lovely modeler but not so great for 3D solid modeling, or so I've heard from someone who works at a 3D print service bureau. Similarly, I don't list Blender, which can be used for modeling but is a surface modeler, so you have to make sure your model is watertight.
Model creation tips: my mantra is "smaller is cuter is cheaper". For display, smaller, detailed models are often more impressive to people than larger ones, plus they're less expensive to make and print faster.
Me, my interest in 3D printing comes mostly from a hobby project, Mineways, for creating 3D print files from models made in Minecraft. I usually use the service bureaus Shapeways and Sculpteo to print my exports, because I print in their full-color sandstone/plaster material. In my experience, Sculpteo costs about 50% more and delivers considerably faster (even with them being in France).