Kate,
Don't be afraid to get one. No one says you have to use it. If you don't want to, don't. I know my grandmother got one and never used the darned thing unless the weather was crappy.
Here in Michigan, all you need is a Dr's note and you can get the hang tag. It's a little more involved to get the permanent plate.
Ya never know, having access to the disabled spots may make you pretty popular with your friends <img src="i/expressions/face-icon-small-smile.gif" border="0">