Russ,
Look under Members Files @ Dub-U-Tub. You will see my chrome spare. I use 5 1/2 x 15" w 185/65/15s on the car, but the spare is a 4 1/2" x 15 with a 135 mounted on it. This is the set up Kirk did for me. I have added a scissors jack under the wheel and a collapsable lug wrench, pluse a bag with essential spares and tools.
For all that, I too highly recommend a Cell Phone, a blanket, and a can of fix a flat. The one and only time I have been roadside stranded was when I cratered a mexican crate engine,,,, the spare didn't help out much...haha.
Besides peace of mind, the spare does help tremendously as ballast for a light front car with an engine in back... specially with a small 8 gal tank. I will go with a 16 gallon this spring.
Jim