How can I remotely delete sensitive data and log out from a stolen Mac? Is there any software or a procedure that would allow me to


log out of all services (gmail, dropbox etc.)
and/or delete any sensitive data remotely


...from a machine that has been stolen?
Find my Mac
Find my Mac is free and part of iCloud. Included features are:

localize your Mac (internet connection required, Email notification)
remotely lock your Mac to protect privacy
remotely wipe your hard drive
play a loud sound
display personal messages on the Mac

 
You need a Mac computer with Lion to use this feature.