I picked this up from Chris Williams when he posted about Caligari 7.6 being free for the taking.  This is very, very cool.  I have always thought 3D modelling was way cool and actually bought Caligari TrueSpace 5 many, many years ago.  Everything I made was crap but it was still fun to learn something like that.

From the Caligari website, cool stuff for devs leveraging Virtual Earth or XNA...

An entirely re-written X format exporter lets you save your trueSpace creations to load into game engines such as XNA to develop games for Windows or the Xbox 360.

Also included is an export to Virtual Earth which will let you place your 3D creations straight into Virtual Earth from trueSpace. Now you can place whatever you make into real world locations in Virtual Earth and share them with others!

trueSpace also supports import from a wide variety of formats, letting you take existing objects and use them in Virtual Earth.

For those of you that don't know, Caligari is actually owned by Microsoft now.  Of course, I find out about the free software from Chris and not from an internal announcement!!!!!!!!!!

Download here - http://cart1.caligari.com/web/Truespacemainreg.aspx