How can I check which applications have been granted root access? I have an SGS i9000 with Android 2.1 and I installed a lot of applications before I fully understood what "root" was.  Now I naturally want to review which applications I gave root access.  How can I do this?
If you root your device using one of the more modern methods, then you should have a SuperUser.apk installed that will prompt you before any apps are given root access. The SuperUser application also keeps track of the applications that have been given root access.

If you don't know about rooting, there is no way you have an apps that uses root except if your phone is a second hand, and the previous owner did not wipe and reinstall a stock firmware.