I have one of these:

http://www.amazon.com/Kool-Stop-Tire.../dp/B001AYML7K

and one of these:

http://randonneurextra.blogspot.com/...1_archive.html

which I bought here, although it looks like they are out of stock.

http://www.biketoolsetc.com/

Both are light enough to carry on a ride. The VAR fits easily in my seat bag. The Kool Stop is longer. It fit in my old handlebar bag, but when I retired that I had to keep it in my jersey pocket. So now I generally use it for home tire changes, and the VAR is with me in case of tire problems on the road. I find the Kool Stop is a bit easier to use.