Excuse me if this product has been mentioned before…
A company called Derma Safe makes a very small lightweight razor/knife that I think is ideal for weekend trips. Handles come in black or bright orange.
http://www.derma-safe.com/folding-utility-knife.htm
Pelouze says: .2 ounce / 8 grams.
I was able to get them in single quantities, $1.50 each, from County Comm: http://www.countycomm.com/straightrazor.htm
I find them much more usable with its small handle than a standard bare razor.
Enjoy.

