There are a lot of helpful CSS properties out there, available for use, that I am simply not aware of. I came across one recently while reading a post from Sacha Grief on my iPad. When I tapped on a link, there was a nice highlight colour applied. When designing a site, I know I've struggled at times to pick appropriate styles to indicate both a link, plus the state of the link when tapped.
I checked out Sacha's site on my Macbook and discovered this nice entry. He uses a different colour for this property than what is used with his :hover declarations for links. It's a helpful property in that it gives a visual indicator that you're tapping a link on an iOS-based version of webkit. Good to know!