Change size of bounding box

I did a search and didn't find this requested before, so please forgive me if it has been. I would like to see a straightforward way to change the bounding box around an object or group of objects without changing the pivot point. I'm making jewelry in Second Life, and the game limits the size of objects to .01 meter, but much smaller objects are required, so the "trick" has been to upload the smallest object possible with a much larger bounding box so it can be displayed smaller in-world. But changing the bounding box can be a trick in itself, requiring invisible faces or edge splits or other hacks -that sometimes stop working when either Blender or the SL client is updated.
I'd really appreciate a simple, intuitive way to make a tiny mesh, then increase the size of the bounding box around it before exporting so it can be uploaded to SL as a larger model. Thanks in advance. :)