Not to knock any sites, but...

http://www.theforce.net
These models are NOT in Poser format, which means they may have to be scaled to the proper size... or they may not work at all. Some models may be in a newer 3ds format which Poser can't read or some models (such as the Millennium Falcon or General Grevious) may be too large to load into Poser. (One of the Falcon models has over 450,000 polygons, which brings Poser 6 to a dead stop.)

http://www.3dgladiators.com
Read their agreement before proceeding to their download section. As of June 2005, they require you to be a member (which is perfectly fine), but they also require that you post at least 5 messages in their forums before you are allowed to download any of their free items.
And, yes, their freebies are made for Poser, but they are approximately Poser 3 quality... on the other hand, they are the only ones with Poser versions of Darth Vader, Jar-Jar Binks, Yoda, and other characters.

We at Vanishing Point pride ourselves on making accurate Poser versions of the Star Wars vehicles that have fully moving parts as well as being to the scale of the Poser people... well, to a point. The Star Destroyers and Death Star are not to scale. ;)
We have the complete collection of Dodger's lightsabers (up to Episode I) and we are the ONLY site to have Poser versions of the X-Wing, B-Wing, AT-AT, AT-ST, and more.

--John

VanishingPoint... Advanced 3D Modeling Solutions