Have a mac, here is how to check if your infected. *Open terminal run this
defaults read /Applications/Safari.app/Contents/Info LSEnvironment and this defaults read ~/.MacOSX/environment DYLD_INSERT_LIBRARIES
If both those commands come back with something that ends with "does not exist" you are clean. Otherwise go here: http://www.f-secure.com/v-descs/trojan-downloader_osx_flashback_i.shtml
If you are clean, be sure to run software update, and update java (if not already updated). Java is where the vulnerability is.
http://www.f-secure.com/v-descs/trojan-downloader_osx_flashback_i.shtml