Yes. IfAnd you can make it work through most firewalls if you're both using Messages. Messages will broker the handshake to start the session and your firewalls allow forthen turn it, you can share your screens even if you're not over to the same local networkscreen sharing app.
Start up Messages and make sure Screen Sharing is enabled:
Find your buddy in your contact list in Messages and click on them. Then select Buddies -> Share My Screen with Buddy... or Buddies -> Ask to Share Buddy's Screen... from the menu bar to initiate a screen share session. You can share control with these sessions.