Mail & iCal with Exchange

[Velocity]

Hello,

I have Mail & iCal setup to work with Exchange 2007 and all is working fine but for the life of me I cannot find a way of opening somebody else's calendar or opening another mailbox I have permissions to?

Any ideas, I don't want to use entourage
Thanks

 

[Feek]

Can you not just add a second account within mail.app?