Thursday’s the big day for Verizon, when it starts selling its version of the iPhone to the general public. Both Apple and Verizon began accepting pre-orders from the general public on Wednesday morning to accommodate demand; customers who buy from Apple can have the phone shipped to them or can arrange for in-store pickup.

[ad#Google Adsense 300×250 in story]Be warned, however – Apple’s already telling customers that phones ordered today may not ship before February 18, 2011.

Apple and Verizon briefly accepted pre-orders last week from existing Verizon customers who wanted to upgrade to an iPhone. Both companies sold through the pre-order stock within hours. Verizon later noted that its iPhone pre-orders broke all Verizon sales records.

The Verizon iPhone looks and works like the iPhone available from AT&T, but supports Verizon’s CDMA networking technology instead. It was unveiled at a Verizon press event in January attended by Apple COO Tim Cook and other senior Apple executives.