You can use some online desktop sharing tools. I always use skype or AA_v3.
Here are some links useful for Screen Sharing 😉
http://yuuguu.com/
http://www.crossloop.com/
https://secure.logmein.com/home.asp?lang=en
http://showmypc.com/
http://skyfex.com/
http://www.teamviewer.com/index.aspx