The robot I built used HiTechnic's IRSeeker sensor and the Compass sensor. Now, LDD does not yet have HiTechnic's sensors included in the palettes, but that didn't stop me from creating some building instructions for it with LDD. You'll just have to substitute the Compass and IRSeeker for the Light and Sound sensors shown in the steps.
You can download the (zipped) .lxf file here.
And you can download the 3MB zipped file containing 28 PNG images containing the steps to build this robot here.
The robot may not be that impressive, but consider that it took me less than 30 minutes to build it using LDD and another 30 minutes to take and crop screenshots of the 28 building steps. In about 1 hour, I've been able to not only design a simple bot in LDD but also create fully functional building instructions for it that can be shared with anyone who wants to build it... modify it... add on to it...
I'm also providing these building instructions to show you how easy it is to create them for places like NXTLOG and other websites. Instead of just a few photos, try building your robot in LDD, take some screen captures using the Building Instruction Player (a tool in LDD) and uploading the images to NXTLOG or other and let others try out your design.
Have fun.
Jim