I just found an interesting little software toy. It's a serious unit converter with a twist.

The details:
Do you want to know how many miles you'd travel in a Light Year? How about how many meters there are in a Roman Mile? ESB Unit Conversion Utility will easily convert between units of measurement.

Some of you may find it useful. I have so far. I can figure my travels at light speed around the universe.
http://www.esbconsult.com.au/esbcalc/esbunitconv.html

BTW: Best of all it's free..............