Attached Link: http://www.ldraw.org/

You can find a number of 3ds bricks and models by doing a Google search for "3ds lego" (without the quotes).  I did the search and saw a number of sites that I downloaded the bricks from, but I'm doing to let you do the searching to get them.  The bricks all readily import into Poser, but would have to be resized.  If you want to import them at a consistent size, uncheck Percent of Standard Figure Size.

Of more interest to everybody ought to be the free ldraw software program.  I haven't used it, but it contains 1200+ Lego parts and is a CAD type program for building Lego models and can print out the instructions used to create the models similar to the instruction pamphlet that comes with Lego sets.  The models can also be exported to a format that 3D programs can import.

My visual indexes of Poser content are at http://www.sharecg.com/pf/rgagnon