A reminder that Apple's online store automatically charges local sales tax on your purchases -- which on a $3000 PowerMac can add up.
The following MailOrder vendors only charge sales tax in states in which they hold a presense:
MacWarehouse: CT, NJ, OH and TN
MacMall: CA, TN, WI
ClubMac: CA, TN, WI
These vendors are also offering "Free" Printers and other discounts (after rebate) -- with purchase of PowerMac G5 systems.
(Note: individual states may have their own policies and may require sales tax on internet purchases to be declared at tax-time.)